changed in the united states actually delivered barack obama prepared for his final state of the union address. and on the forth anniversary of her death, a look at why agatha christie remains the world's best selling author.

ten empty chair are now known to have died in a bomb blast in the largest stir istanbul. it happened in the district, an area known for his toric monuments. it is popular with tourists and eight of the dead are german. the explosion was so large it was heard several kilometers away. shortly after convened an emergency security meeting he says the suspected bomber was a member of isil. turkey was already on high alert after a series of attacks blamed on isil including a double suicide bombing in october, that left more than 100 people dead. first here is the report from istanbul been. >> and square is in the heart of istanbul, millions of tourists gave him wonder of

the blue mosque many the museum. >> it was the suicide bomb, yeah, i went there and saw it and came back to the hotel in chaos. everyone was running around. police didn't see this coming they were upset but at the same time they were trying to evacuate the area, because they said a second bomb can go off. >> the person traitors othis attack will be unveiled and they will get the punishment they deserve. i call on all humanity, we

need to stand in vol darety, we need to stand should tore shoulder in the face of install bruin, lyle we did in the attack in paris. >> some in turkey have been expected attacks on turkish soil, since the armed forces launched their offensive against isil fighters. >> in october, at least 102 people were killed and a double suicide is blast on a peace rally. this latest bombing was again aimed at what would be regarded as a soft target, and by thatting foreign tourists it was designed to draw international attention. >> today it was istanbul. we have seen attacks in many places. international terror chooseses different places but the goal is always the same, our free life and our free society. terrorists are the enemy of all free people. yes, the enemies of all man

kind whether in syria, turkey, france, or germany. >> the district is now locked down. people left bewilders that a suicide bomb has torn through their beloved and historic city. al jazeera joins us live now, and unfortunately, this is not the first large scale attack. what is important and significant about the events that unfolded today. it's just been over ten hours since a powerful blast shook the square. spoke to eyewitness news closer to a kilometer away from here, they said that the earth under them shook, one eyewitness said she thought it was the thunder, but saw that it was a clear blue sky. and we understand that soon

after the blast we were told that this was, in fact, the work of a suicide attacker. the turkish government wasn't fast in confirming that this was a suicide attacker, but once they did, we understood that ten people lost their lives most of them foreigners. >> what more do we know about what is behind this attack? >> yes, we were told by the presidents knowing that this was a 28-year-old syrian citizen, who was behind the attack who was the suicide bomber shortly after that, the prime minister said is this this was the work of a daesh member of a foreign

daesh member. the dawn news agency has been quotening police sourced as saying that the perpetrator, the apacker a saudi born syrian who the prime minister's office has said entered turkey, on the fifth of january. legally as a refuge. and even went through formal fingerprint procedures. in which ten people are now known to have died. now the world health organization has allowed the government to allow in teams to aa recess the extent of malnutrition. the u.n. has described the suffering there as the worst seen in the country so far.

aid agent asies are are now negotiating to pull out hundreds of starving people from the town, on monday, aid was delivered to two other towns. kevin kennedy is the humanitarian coordinator, he spoke about the challenges for those fighting in syria. >> it's been a long on going process for years now uh our team on the drowned, the red cross, and red crescent, they are con fronted with security threats. it is an active war zone. shifting front lines and -- imposed by all parties of the conflict, and other parties as well. the population of syria about 4.5 million people are in what we term hard to reach or besieged areas. our access to those people is very very limited.

we need full time unimpeded sustained access to all these areas. >> a pommed out shopping center, 18 people were kimed and gunman stormed the mall on monday. isil says it carried out the attack in the mainly shia district of the capitol. they have been shot dead in separate incidents a 21-year-old was killed in clashes here bethlehem. >> now u.n. backed peace talks over the war in yemen have been delayed. they were due to start on thursday, but they may not

start for another week, but they can't agree on a location. a temporary truce is broken down, which is in desperate need of food and medical supplies. >> houthis gunman heard residents away from their check point at the western gate. >> they are insummitted and humiliated they say we are not allowed to leave the city. more than a quarter million people have no access to food in the city, which used to be well known for the coffee and products. >> dais is under siege by houthis fighter whose control the city. fighters loyal to president control the city's main district. >> what do we do, where can

we go. this is our country. they are in dire need of help. the saudi led coalition backing the yemen government began air strikes last march. more than 6,000 people and 2 million injured. the world health organizations says hospitals have had to stop treating patients because hospitals are overwhelmed. blockades and air strikes are preventing agencies from delivering food, medical supplies and even oxygen. child malnourishment is widespread. >> everything is getting worsedy by day, they soy they won't allow -- efforts continue to fail, activists are turning social media, they hope the #end tias siege

will pressure the forces to allow in aid. they want to remind the world that syria and is not the only place where people are dying from disease, starvation, and shelling. the sister of the jailed saudi blogger has been sent to prison for running the twitter account of her husband who is also in jail. amnesty international says mother of two is being held in the central prison, where her brother is serving ten years for insulting islam. the husband is the lawyer he is also in the central prison, serving some 15 years for speaking out about human rights. still to come for you. as crude slips to the lowest price in 12 years. they go to school in northern

niagara and where education is a battleground.

>> it has identified the suicide bomber as a saudi man, most of those killed were germans. off the government to allow them to send mobile clinics in medical teams to assess the extent of malnutrition. in separate incidents of the

west bank in the latest wave of violence. it's barack obama's final year in office, and it's unlikely to be the usual policy speech. like his achievements with the economy, healthcare and same-sex marriage. but he is also expected to look at the challenges ahead. and frame some of the major domestic and international objectives for the u.s. the the democratic party doing forward. obama will also use in address to add fuel to the fire, voting in the first presidential nomination. in the final state of the union speech, but tell us more about what he is going to be focused on. >> from president obama where he will speak to the members of congress, that will be

gathering in the house of representatives, but you are right, this one is different, it comes in the heat of the election season, so while typically we would hear from a president he would be lifting off a laundry list of things that hoping to accomplish with the legislative and executive branches of government, this time, you are right. it will be more about what he has achieved in terms of his legacy, and what he hopes to achieve in terms of speaking to the american public, encouraging them to vote for another democratic president in the white house to carry on what he considered his unfinished prison. so we expect there will be broad themes and priorities for the nation that will be outlined and we get an idea of what those might be. when we look at the guest list of the first lady, who will be present for the speech, there's going to be a homeless advocate, someone who advocates for climate change, a syrian refugee, that ease are the issues that the president is expected to touch on, but he is also

going to highlight what he sees as i his succees mainly the nuclear deal with iran, improved diplomatic relationships and even some policies we put in place to combat climate change. >> all right, live for us in washington, d.c., thank you. violence blamed has dispoliced mar than 1 million people in the past six years. finally aend thing school. like everyone in his class, he fled from his village after barack obama attacked and occupied it. and has killed tens of thousands in the northeast. >> not to go to school, and if anyone disobeyed the announcement is dead, now in

the camp we get a tradition. >> the nigerian government are are providing mobile classrooms like these. to help children displayed by the violence catch up on their education. >> in the collaboration, the president in the knot east, we have established a mobile i don't want, and mobile units is a classroom that and fully equipped with furniture, and even generators and electricity, and solar panels. and it is really fully equipped classroom that can host 40 children, which is standard ratio in terms of students and teacher ratio. >> but even with these classes running in the morning and afternoon, the facilities in the camp are simply not enough. as many as 70 eastern of children attend the school before the boko haram violence, that figure

significantly increased over the last six years after more than 2 million people have been displaced. >> most schools have been destroyed and hundreds killed. >> although the mobile classrooms may not be enough, they offer children a new start. >> little selma has been around violence since she was born. out of school children aren't able to do it. al jazeera, nigeria. at the peek in 2008, a barrel of oil costs more than $1,247 it has fallen to 30-dollar as

barrel, and that is great news for people filling up their cars. goods and services may also cost less, but it is bad news for oil producing countries. none of these nations are getting enough of that oil to cover their costs. a saudi economist he says the middle east is not to blame for excessive oil production. has much higher costs much highest costs. it is mainly the jump, and the u.s. oil production, that has called over supply. >> she says the country is being directly effected by falling prices and the president is is calling for an emergency opec meeting.

>> nigeria's government relies on 70 to 80% of the income, from the sale of oil, and obviously the plummeting price of the product has had a terrible impact on the nation's ability, on the government's ability, to see through many of the projects that itad hoped to. recently the government said the annual budget and it benchmarked the price at 30 ate dollar as barrel, we are now reporting as low as 31, and there are some indications comes from organizations like morgan stanley, that the oil price can fall to even $20 a barrel. now, what he was calling for in abu dhabi is a tremendous strategy. the major player in saudi arabia, has refused to cut production, and as an organization, these countries have refused to cut production, and some, the nigerians in particular, are are now questioning that strategy, and saying is this right, so it seems to be on

the surface, the division between opec members. >> the south korean electronics giant has settled a long running bat with employees that have developed cancer. harry faucet reports from seoul, some are refusing to accept the deal. >> . >> in that context i am happy with the deal. >> while working in h the semiconductor plant in the 1990's. >> and signs up for a a zerory of preventive measures. the company continues to deny any link between it's factory

environment and the disease this is question. >> i find it very meaningful that this issue has been on the table for a long time, has been resolved through dialog, and i hope all parties stick to the spirit of the agreement reached today. >> some studies have shone the factories comply with international guidance on levels of chemicals and radiation, the company is already settled more than 100 individual cases. >> they had for many years been challenging the compensation is body and it's legal battle against former employees but last year it changes the policy. instead deciding to offer an apology and set up a compensation fund. some are still holding out. they have been fighting to recognize a link between the factory environment and the death of his daughter. from a rare form of leukemia, a link which was made by a court in her case, in three others. the fellow campaigners have signed up in sup is port of the measures bout accepting

the company's money or it's apology. >> until samsung can have compensation, we will continue to protest outside the headquarters. for mr. huang who has become the face of that fight, it is not over yet. seoul. >> a cleric jailed on terror charges has appealed for the conviction to be overturned. he is serving a 15 year sentence for funding a terrorist training camp. he was at the court. supporters have their anger at the district court, a town in central joba. near the island where he is imprisoned security in town is it to. bashir is the spiritual

leader which is internationally recognized as a heart line islamic organization. in a statement, the armed training camp that led to his conviction in 2010, but insists that his donations to the camp were meant for humanitarian pumps. my role in this group is unimportant, but i received the heaviest punishment, so it is clear this is a conspiracy not a fair sen is tense. >> me used his rare public aa pierce as an opportunity to lash out at police, prosecutors and judges. >> the name of ab a buebashir is never mentioned in the primary allegation at the beginning of the hearing. he is not involved in the mentioned terrorist act, put why does he become a terrorist. in the following hearing, the verdict is a mistake. >> hundreds of sup is porters have traveled for many hours to show their anger over the terrorism conviction.

emotionally, they have demanded his release. it is now up to the supreme court to decide if evidence presented fie years after the conviction will be enough to release him. >> from prison, they pledged alliance to isil in 2014, he says his son has since withdrawn his support. i believe he doesn't support them any more, the problems are not like they were before. >> . >> al jazeera, central jobben ba. >> an aa peel between the philippines and the u.s. has been thrown out by the supreme court. demonstrators were unhappy with the agreement to let the u.s. boost it's military presence in the former colony. a deal was challenged by

lawmakers who said it was unconstitutional, and forces the philippines to give up it's sovereignty. >> 40 years after the anniversary of her death, agatha christie remains the world's best selling author. not only that she is also the most successful female play wright ever. 've barker reports on her enduring popularity. >> following in the footsteps of the most famous crime writer in a city where she fist found fame. the journey begins in china to be, where used to be the detection club. members included the writers dorothy l sawyers and g.k. chesterton. while agatha kristi was her president. today it is rah chinese restaurant. they discuss whether murder was justified you know, work out plots and sometimes they would collaborate and work

together and produce some books. >> and they also have an an unusual initiation, involving a skull called eric. >> you would have to place your hands on eric's head, and swear true that, a certain part of theser is monny, his eyes would light up. >> agatha christie is best known for her 83 detective stories. making her the most successful novelist of all time. she has only been outsold by shakespeare and the bible. >> the stories also led to a string of film and television spin offs. >> the characters are even adapted into japanese cartoons. but the first laugh was for the stage.

>> much more fun. >> when the mouse trap was first staged in 1952, kristi only expected it to last a few months. it is the world's longest running play. >> it is the classic who done it, and the brilliance is that it is a group of people trapped in a place. no one can escape. which immediately brings attention, throughout the play, she makes all of them possible murderers. >> in the heart of london's theater district, is a statute of christie set within a book. her work continues to generate royalties of $4 million a year, and last year, ten lost plays were rediscovered. keeping audiences and armed chair detectives guessing even beyond the grave. >> al jazeera, london.

>> you can get the latest on everything we are covering right now. which the government is saying was perpetrated by a member of isil. more on that in a moment's time, aljazeera.com. >> this is "techknow". a show about innovations that can change lives. >> the science of fighting a wildfire. >> we're going to explore the intersection of hardware and humanity, but we're doing it in a unique way. this is a show about science... >> oh! >> oh my god! >> by scientists. >> tonight, saving the macaw. >> i'm in the peruvian amazon and we're on the search for endangered macaws. >> now techknow is on a one of a kind mission. >> look at those wings. >> the macaw; graceful, elegant,