still rights cases. it will certainly be an uphill battle. the republican race for the white house narrows to three contenders while democrat hillary clinton extends her lead. you're watching al jazeera live from our headquarters in doha. also coming up, at least 15 killed in pakistan as an explosion rips through a bus carrying government employees. civilians rally against the government as diplomatic efforts push on to stop the war. the women keeping the peace and protecting families in south

sudan. five big states have been choosing their preferred candidate for november's u.s. presidential election and the two front runners have pulled further ahead. donald trump pushed one of his rivals out of the race. hillary clinton built on her lead as well. take a look at the latest numbers. donald trump has now secured 621 off 91237-- off 91237 delegates he needs to get the vote. john kasich won in his home state of ohio. while the other remaining challenger ted cruz hasn't won any more states is also missouri has yet to declare it's results. hillary clinton now has a 1094 delegates. that has stretched her lead over bernie sanders who has 774.

a report from washington dc and begins are the latest republican candidate to pull out >> reporter: he went down fast >> whilst it is not god's plan that i be president in 2016 or ever, and while today my campaign is suspended, the fact that i've even come this far is evidence of how special america truly is >> reporter: donald trump delivered a crushing defeat to marco rubio forcing a bitter end to a campaign based on optimism. >> the fact is we have to bring our party together. >> reporter: then there were three narrowing the republican race to a contest between ted cruz and john kasich. who won in his home state beating donald trump breathing new life into a winless campaign and raising the chances that

trump will not lock up the nomination before the nomination. >> i have to thank the people here. i love you. we are going to go all the way to cleveland and secure the republican nomination. >> reporter: john kasich's victory could lead to a messy party fight all played out in public that hasn't happened in decades. >> if we do have a contested election on the republican side, it will go back to the old ways, when there were no primary elections and the parties did get together and make the decision on their own as to who the nominee would be. >> reporter: hillary clinton swept big prizes. the electoral math just got harder. the latest round makes it likely that the front runner will seize

the nomination and less likely the republican front runner will. clinton pivoted to the general election and trump >> our commander in chief has to be able to defend our country, not embarrass it. engage our allies, not alienate them, defeat out adversaries, not embolden them. >> reporter: a look at the race to come peter matthews is a professor of political science joining us from l.a. with donald trump's victories on tuesday night over the u.s., does this mean that the moment of truth is nearing for the republican party? >> not entirely. certainly they're in that direction because donald trump has got the most delegates and he needs to win 50% plus one in

order to win the nomination at the convention. he needs to win 62%. that is a tall order unless he can win those winner takes all states. he is doing well. he can certainly win them. there's a chaps that he can win them still and take the nomination. it could be april chance where the party leaders will then wheel and deal with the other candidates and put it together if there is a brokered convention on the republican side, would it go back to the old ways where the parties do things that there were no primaries and the parties decide by themselves who the nominee would be? >> yes. it would. it would be the internal leadership that will decide that. they will turn off republican voters from the outside. trump brought in a whole lot of new people from the outside dissatisfied with the system,

anti established, saying their jobs are going overseas. this is the discontent that both sides are feeling. that's why bernie sanders has been done so long there are - you're saying that dump does have a lot of support. there are senior republicans saying they will never support him. how far are they willing to go to block him? >> i think they're going to go as far as they can because they don't want to have donald trump. they feel if he wins the nomination, they believe the party will disintegrate overall. they don't want to see that happen. you saw romney make a speech about why he shouldn't be nominated. when this happens, the party is in danger of disintegrating

you were saying bernie sanders has support, but numbers don't point to that. hillary clinton clearly in the lead. is there anything that bernie sanders can do? >> here is the difference of the two sides. the rest of the republican primaries, many of them are winner take all. if bernie sanders wins 45% of the vote, he gets 45% of the delegates. he can still hang in there. hillary clinton has to have 2300. she has 1100 plus super delegates that could switch sides. it's still up in the air in terms of the f.b.i. investigation of the email situation and what happens with the possible indictment. i think so far she looks strong. she is winning a lot of states. it is important that she did that. it gives her a big boost. than sanders is not out yet

we thank for joining us. at least 15 people have been killed by a bomb that exploded in a bus in northern pakistan. it happened in the city of. about eshawa. nearly 40 others are injured. >> reporter: an explosion on a bus carrying government officials appears to be a timed device. the bomb being placed close to the tool box. also reports that the bus driver was still able to drive although he was critically wounded. the rescue efforts will get underway. according to the local hospital sources there are dozens who are in serious condition in hospital so the likelihood of the death toll going higher cannot be ruled out. at the moment known has taken

responsibility but this is, indeed-- no-one has taken responsibility, but this is indeed an tack. such an that tack took place against such officials. also travelling on a bus in which 17 people were killed saudi-led air strikes have killed more than 100 civilians in yemen. that's according to shia houthi rebels. the saudi-led coalition says it is looking into the reports. the charity doctors without borders says more than 40 kill i can't answer were-- civilians were taken to the hospital it has been five years since anti-government protests began in syria. eventually leading to all out war. demonstrators have returned to the streets to mark that anniversary. the protests took place in a number of towns and cities with many chanting for the removal of

president bashar al-assad. the protesters also demanding an investigation into what they say were crimes committed by the syrian forces and during russian's bombing campaign. u.n. special envoy to syria says he has proposals from both side of kwlingt outlining their visions for political transition. staffan de mistura is meeting a day after opposition talks. on the grouped russia is withdrawing most of its forces from syria. james bays reports. >> reporter: the man in charge of mediating between the sides in the syrian collect, u.n. envoy staffan de mistura, said he didn't believe the timing of the russian announcement as his talks were restarting was a coincidence. >> we consider this a significant, i repeat, a significant development and now we hope and we shall be

expecting and hoping that this will be happening, that we will be seeing this decision bringing some positive influence on the actual progress of the talks. mr staffan de mistura had a meeting with the main opposition block, the high negotiations committee on this, the 5th anniversary at the start of the war. they believe the russian pull out is positive news. >> this will help us really to reach a political agreement and really achieve something for our own people there. i hope it will be an end to all these fights in syria >> reporter: there has been some suggestions that there's a deal between u.s. and russia. if part of that deal was for president bashar al-assad to stay on for a time, would you be prepared to compromise on that. >> we don't know if there is such a deal, but we know that there is big efforts from the states, from european countries,

that really made putin take this position. >> reporter: difficult diplomatic answer, but one of those represent possessing the armed groups in the hnc in his first television interview in geneva was more forth right. >> translation: we are for a political transition, but without the presence of bashar al-assad and we will not accept him having a role. >> reporter: the start of the russian pull out has changed things. how much is not yet clear. the government delegation are likely to be uneasy. the opposition a slightly more positive. however, they're still beary about russian motives. perhaps putin has still more surprise $up his sleeve lots more coming up, including unclassified and stuck in limbo. the refugees struggling to find a path forward in greece. plus the metro rail system in the u.s. shuts down for an entire day. details coming up.

the top stories on al jazeera. u.s. republican presidential candidate donald trump has won in florida, north carolina and illinois. it was a goodnight too for hillary clinton. at least 15 people have been killed in a bomb explosion on a bus in pakistan. the bus was taking employees to work in the city of peshawa. staffan de mistura has said he has received proposals from both sides of the conflict outlining

their positions for a political transition. he will hold discussions with representatives of the government. in turkey at least 20 people have been arrested after police raids in istanbul focusing on the p.k.k. those detained included lawyers associated with the p.k.k. according to turkish media reports. the arrests come as confrontations continue between the security forces and armed groups following the suicide bombing in ankara on sunday. four police officers have been wounded in a shooting in the belgium capital brussels. they're investigating suspected links to november's paris attacks. at least one suspect has been killed. >> reporter: the raid was coordinated by the belgium and french police working together to search for suspects linked to the paris attacks that killed 130 people in november. armed officers surrounded a building in the forest district

of brussels. gunmen holed up inside. >> translation: shots were fired this afternoon and there were two people hiding in a building. the security perimeter was set up by the police and then the security forces arrived. operations are still ongoing >> reporter: at least four officers were injured. witnesses say they saw two suspects escape over the roof tops. snipers position themselves above ground as the area went into lock down. during another round of gunfire a suggestion expect was killed. he was found with an automatic rifle. >> translation: they asked us to evacuate the bus. we got out, walked, and i heard gun shots near the church and school. i walked away and stood at the bus stop. i do not in this part of brussels there is deep shock at the events unfolding here. children who have been sprayed

from their families and the lock down returned home but many of the streets were deserted. >> parts of this neighborhood are still cordoned off as police continue to search the streets. people are being told to remain on their guard. >> reporter: several of the paris attackers are known to have come from brussels, including 26 year old suspect salah abdeslam who is still on the run. it is understood he was not the target of this raid. the resistance which the police encountered in forest seems to have taken many here by surprise. there will be questions about why those involved in the police search were not better prepared for what they found in greece thousands of refugees have been trapped as neighbors balkan states shut their borders. while refugees from syria or iraq are in proper camps, those from other countries are being forced to live in makeshift shelters.

many european governments consider them to be economic rye grants and not refugees. >> reporter:-- migrants and not refugees. >> reporter: here greece has been holding a giant holding pen for refugees. other countries are up in a camp set up by volunteers from across the globe. a place here is the only welcome they have received and, perhaps, the warmest they will get >> some people are facing the big problem. they are not exactly taking just like that. what is going on? i have no idea. it's a crucial time for me. i have never, ever faced this situation in my life history. >> reporter: those here are mainly from afghanistan, pakistan and morocco. the e.u. can considers them economic migrants and therefore

unqualified for refugee status. the number of people here rises every day. it's a limbo for hundreds. they cannot go any further. the border is closed to them. every day the volunteers struggle to give them the most basic of humanitarian assistance to the desperate people. this lady is from denmark. >> i'm amazed by this. i'm amazed that they can still smile. i am aamazed they can smile and thank you. you're not recognised. it would be hard. >> reporter: as europe pins its hopes on the talks, many fear they will have to return. >> translation: we can't go back to our countries. what will we live on if we return. >> reporter: at least the refugees have safety here and

the destruction of a game of cricket in a dull setting. their future in the country hosting them offers a bleak prospect. >> reporter: a u.s. student has been sentenced to 15 years of hard labor in north korea for crimes against the state. he was arrested in january for stealing a propaganda slogan poster in the capital pyongyang. the 21-year-old confessed to his crime in february. he said he wanted to take it home as a souvenir the leader of china has defended his position that the economy expand. it expanded by 6.9%, the slowest rate of growth in 25 years. a target of 6.5 set is set going

forward. >> reporter: it is expected the china's national congress has approved the country's next five year plan, 913th since the foundation of the peoples republic of china. these five year plans are a legacy of the command economy. after that happened, the premier met the media. this happens once a year when he takes questions from selected journalists, questions which are generally vetted in advance. most of those questions concerned the economy. the premier said he was convinced there would be no hard landing for china's economy. he also said while there would be ups and downs, if things got series, china's government had the means to deal with that. basically throwing more money into the system. he also touched on the sensitive issue of what to do with workers in loss-making state-owned industries like the mines and steel millions. there have been protests in the north-east of the country involving thousands of miners who say they haven't been paid

for weeks. the government knows it has to deal with these bloated enterprises. they absorb billions of dollars of money and they're incredibly inefficient. the government is beginning to wield an axe. that means that many mines and steel millions are going to have to close and, of course, tens of thousands of workers are going to be made redundant. the government has set aside a fund of some 20 billion dollars to cover things like redundancy and retraining and says if more money is needed, it will be found. the premier has said this is going to be a difficult year for china. that is especially true for miners and steel workers the second biggest subway system in the u.s. has been shut down for 24 hours. the metro in the capital is undergoing an emergency safety investigation. online taxi services are offering discounts to get people to work. some have left it up to their

employees to show up if they can. >> i have to do what i do and go to stay at my sisters >> i told my boss immediately and he super, send out nobody come in tomorrow. treat it like a snow day the government in niger is building a rail link. 91.8-- 91 million dollar will give access across the area. >> reporter: it has taken almost a century to arrive, but the train is finally here. the government of niger says it's the biggest project the government has seen recently. >> translation: the train is now a reality. we already have 140 kilometers of rail that are completed and useable. considering the reliability of our partners, we are sure the

project will be published. >> reporter: a french company began work on the five-year project last july. the first section linking areas is already completed. this is where the dream began some eight years ago and that was in 1936 when there was the beginning of a railway. that project was never completed. the central railway station that was supposed to be built here never saw the light of day. at the new terminal station several trains are already parked awaying official inauguration later this year. opposition leaders doubt 91.8-- the 1.8 billion dollar project will have an impact >> it has no validity or positive impact. it could be more useful in the

mine areas. >> translation: we cannot feed hunger through talking. we need to act. a railway is the best means of trance on porting goods and people. a railway will surely help us transport our minerals. >> reporter: they say they will be happy to stop using their wooden boats to ship their produce. >> it would be good. >> reporter: for almost a century land locked niger had to rely on trucks. with the construction of the rail line, that effort will be much easier. the train many here hope will help the country take a giant step towards a better future a report that brazil's former president will accept the

position in the current president's cabinet. the main opposition says the appointment is to protect him against money laundering charges. he informed his closest advisors that he would accept a post ahead of a meeting with rousef on tuesday. she was recently questioned by police in relation to the probe into the oil company. argentina's coast guard says it sunk a chinese fishing boat for operating illegally in it's waters. argentina says the boat did not respond and tried to ram one of its vessels at which point the coast guard shot at it several time. four crew members were rescued. others were later picked up by another chinese vessel. a woman's peace-keeping force has been formed in camps south sudan. they patrol the area in juba.

they're on the lookout for unaccompanied students. >> reporter: meet this woman. she is the leader of a team of female peacekeepers protecting families at this camp in south sudan. she says she want to give a message of peace to her community. >> translation: we don't want women fighting each other. >> reporter: she and her colleagues are trying to reduce the violence that happens often in these cramped conditions. people around here moved here when there was issues elsewhere. this area is droled by the government. people say it's not safe to venture out. the women peacekeepers come from the community. it is easy for them to hear about what is going on. they catch up on the news and

lookout for any potential problems. after years of living and you tarpaulin and existing on minimal food and water, crowds can turn angry very quickly. in a situation like this where food is being sdrktd, the force can be a very soothing presence. they come unarmed in contrast to the peacekeepers and they're not threatening to the crowd. the severity of the cases they deal with varies. on this day it was a boy being bullied by his friends. on others it could be domestic violence or reuniting lost children with their families. at the end of the day of her patrol she reflects on the benefits she and her colleagues have brought to of camp >> translation: my job is positive because since we started no woman has fought with another woman. the women wearing these pink shirts, if we find people fighting, we stop them >> reporter: the people in this camp say they want their leaders to stop fighting so they can return to their homes. until they can do so, mary and

her team are doing their part to make sure they're safe where they are much more on that story on our website at aljazeera.com >> the us is now the world's largest oil and gas producer, in part because of what's happening here in north dakota, where advances in fracking have unlocked crude oil in the bakken shale formation in the western part of the state. north dakota is now producing more than a million barrels of oil a day. ten years ago there were fewer than 200 oil-producing wells in the bakken. now there are more than 8,000. >> they call it boomtown usa this is where all the money is. it's crazy the amount of money you can make here.