>> east caracas, in the upscale neighborhood of altamira... an outpouring of anger at venezuela's government is met with a show of force. ...and we're caught in the middle of it. >> we've just seen tear gas being thrown. the police has showed up. everyone's running in this direction. >> since february, protesters have marched, blockaded streets, and fought running battles with the police. more than 40 people have been killed...over 3000 detained. >> so some of the protesters are now being arrested.

but it's incredibly confusing. there's objects flying in all directions. there's even tear gas coming from the top of that building over there. it's hard to see what's going on. they're using pepper protesters. >> the unrest has generated headlines around the world of a ruthless dictatorship crushing dissent with violence but in venezuela, there are competing narratives. ...is this an authoritarian crackdown, or a clash between people with radically different visions for the future of their country? a year after the death of hugo chavez, fault lines is in caracas to find out what's really going on in the streets. >> in venezuela, the former

president looms larger than life, even in death. the policies chavez implemented to redistribute oil wealth were polarizing from the start. in his first five years, he faced a coup, an oil lock-out, and a recall vote from the country's elite. chavez survived it all, pushing forward what he called the "bolivarian revolution" and cutting poverty rates by more than half. he won three more terms in elections the international community universally recognized as free and fair. it's may first, and thousands of his supporters are out celebrating workers day, singing anthems that celebrate the legend they call "comandante". his successor, nicolas maduro is keen to show that despite months of anti-government protests, the chavez "evolution" continues.

>> but maduro is no chavez. he won the last presidential election by a narrow 1% margin. and since chavez's death, problems that have plagued this petro-state for decades have grown more severe. >> it's true that we have the highest inflation in the world, with 59% for these last twelve months. it's true that we are not able to obtain milk or sugar or oil when we need in any supermarket. it's true that we are losing quality of life. >> an overvalued currency and dependence on imports has created supply problems, making long lines outside supermarkets like this a part of daily life.

these are among the issues that have brought protesters into the streets of wealthier areas of the capital for months. but if you go to the poorer neighborhoods - like petare, the city's largest "slum" - few seem bothered by the long wait to buy groceries. >> nelvy carmona tells us she's been standing in line at this state-controlled market since 5 am. >> well everything being sold here at the subsidized rate is basic foodstuffs. it's things like beans and milk and sugar. and you can see on the packets here there's actually revolutionary illustrations with an article from the constitution saying every venezuelan deserves the right to a free education. >> yajaira campos manages the operation. she says inflation is a big problem for everyone, but that here in this neighborhood there haven't been any protests.

>> on the other side of town, caracas's wealthier residents line up for cappuccino and italian ice cream. while those participating in the protests aren't exclusively middle and upper class, it's in these neighborhoods - the most affluent ones in the city - that the majority of the blockades have occurred. >> well sitting here it doesn't look like the kind of neighborhood where people are suffering from an economic crisis. but this is actually very close to one of the main protest encampments. it's just down the road here. >> a few blocks away, protesters are holding a birthday celebration for the leader of voluntad popular, an opposition party. leopoldo lopez is in jail, charged with instigating the violence that erupted at the first major caracas protest in

february. his wife, lilian, is now lopez's public face while he's behind bars. >> lilian, one question in english: who do you blame for the violence and the lives that have been lost? >> resistencia! resistencia! >> while voluntad popular blames the government for the violence, they've used the protests to push a radical strategy. in spanish, it's known as "la salida" or "the exit" - they're calling for venezuela's elected president to go. ...and they're refusing to join the dialogue between the

government and a group of moderate opposition leaders. >> what comes next? what is your strategy? what are you planning for the next -- >> even commentators sympathetic to the opposition, like luis vicente leon, say voluntad popular's solution can only make things worse. >> if you are not negotiating you are creating some kind of coup. even if you have the right to defend your rights, if you create a kind of rebellion, you have to be strong enough to win. because you cannot try to kick maduro out and pretend that he is not going to defend himself. >> back in altamira, the national guard has assembled around the charred remains of a

police truck. protestors ambushed it, and set it on fire. the following night, it's a subway kiosk that's attacked. >> you know this is the second time in two nights that we've been to the scene of an arson attack in the same neighborhood. and the police have shown up in force. but so far at least, the situation seems to be calm. >> just down the road is one of the encampments students have built to keep the protest movement in the streets. one of the camp's founders, gerardo says his people carried out the attack in response to arrests of their supporters earlier today. >> the site is tightly guarded, and there are shrines displaying evidence of government repression and commemorating protesters killed in the violence.

though there have been deaths on both sides, gerardo says the responsibility lies with the government. >> he has hundreds of pictures of people he says were injured by security forces during the protest, collected from social media. >> but it's photos of people he calls "colectivos" that carry the most sensational allegation - that the government is using armed gangs to repress and intimidate protesters.

>> suddenly, word goes out that police are on their way. >> protesters scramble for their gas masks, and gerardo runs for cover...but only after telling us to be ready for a major action the following day. the raid turns out to be a false alarm this time, but it's a sign of what's to come.

>> on tech know, >> the system is paying attention... >> life saving technology... >> i definitely slowed down as a result... >> transforming the way you drive... >> maybe crashes won't happen any more... >> smart cars of the future... >> whoa...i would have driven straight through that... >> tech know, every saturday go where science meets humanity. >> this is some of the best driving i've every done,

even though i can't see. >> tech know. >> we're here in the vortex. only on al jazeera america. >> there have been people murdered in venezuela. there have been people detained in venezuela, indefinitely... >> in washington, some in congress have a simple interpretation of what's happening in the streets - and what the us response should be. >> there has been a bill filed in the congress concerning sanctions against individuals related to and in the government of venezuela for human rights violations committed against their own people. >> these human rights violations were part of a systematic practice by venezelan security forces... >> the accusations laid out before congress are grave: human rights watch says venezuela's government is using armed gangs against peaceful protestors. >> we found that security forces tolerated and sometimes collaborated directly with armed pro-government gangs that attacked protesters with total impunity.

>> it's about the venezuelan people. >> for now, the state department is resisting sanctions. >> i think they would serve to reinforce the narrative of this being about the venezuelan government standing up to the united states. >> we tried speaking with the venezuelan government for this report. all of our requests were refused. >> outside the courthouse in downtown caracas, gerardo is waiting. he wouldn't tell us what the students have planned - but suddenly, it starts. they're chaining themselves together outside the court in protest at the thousands of detentions since the unrest began. >> the security guards have just come out from the court and they're trying to cut the chains. the protesters are trying to stop them. >> the students have been praised as national heroes by venezuela's opposition...but they provoke a different reaction here.

>> you can really see the tension between the two sides here onlookers here confronting the protesters. the amount of anger here - people are furious that this action is taking place. >> it doesn't take long before the national guard steps in with force. >> as the air clears, the confrontation we saw raises questions: >> why would you take it upon yourselves to engage

with the protesters and confront them yourselves? >> are you part of a "collective" in any sense of the word? so you are part of a "colectivo" >> if everybody abroad thinks that we're just in the middle of a dictatorship with the people in the government trying to destroy the rights of everybody, we can create a mess inside, because they want to intervene.

and this is going to put this worse. because the country is divided. and it's true that maduro has an important support coming from the poor people here in venezuela. >> the groups who are known in venezuela as armed pro-government colectivos are ones like this. with roots in the leftist guerrilla movements of the 70s and 80s, the tupamaros sprang into action to defend chavez against the coup he faced in 2002. >> now, under leader jose pinto, they've morphed into a political party that supports the revolution.

>> but while they have a proud history of armed struggle, accusations that colectivos are violently repressing protesters have made the tupamaros shy of even talking about weapons. even their security guards on their motor-bikes aren't openly displaying guns. >> how come there's no police protecting this march? >> while these are the people who've allegedly been terrorizing protesters, the case against them isn't immediately clear. >> so out of everyone we've spoken to about this, there's nobody here who would deny that the revolutionary colectivos have the capacity to protect not only themselves but the revolution. but they've received orders from the very top not to display any of those weapons. so we're not actually going to

see any of those guns at all. >> mario betancourt is the director of provea, a venezuelan human rights organization that has been documenting the colectivos' alleged role in the repression. >> we'd love to see some of that evidence. it's been difficult for us to really get compelling proof of the things that people say are going on here.

>> juan montoya, a colectivo leader, came from a neighborhood called 23 de enero, where those groups are said to control the streets. he was one of the first people killed when the protests started, and he's among at least 7 members of the security forces who've died in the violence. if he's the best example of police and colectivos working hand in hand to terrorize protesters, it's not much to go on - he's been dead since the violence began on february 12, and can no longer be held to account. at the headquarters of this colectivo, it's montoya's work as a community organizer that's remembered.

>> genaro garcia is the leader of the group called catia presente >> while the term has become demonized outside venezuela, garcia tells us most of the groups are simply groups formed to help organize a particular community. well it's saturday morning - looks like little league practice. kids from the neighborhood playing basebell. you know we've been hearing a lot about colectivos as pro-government armed gangs terrorizing protesters. this is a colectivo too. the group says the resources they receive from the government are used for sports or education projects - they're hoping to build a university on this site. there are activities for kids of all ages, and food for everyone.

no one here is brandishing weapons, and garcia denies that anyone in his colectivo is armed. so when the opposition says that there are acts of violence being carried out by colectivos, there is no truth in that whatsoever?

>> for international human rights groups alleging venezuela's use of colectivo gangs to repress protestors, one of the touchstone examples took place here, at the central university of venezuela. it's a highly politicized campus with a history of fighting between students who support or oppose the government. but on march 19 - with the protests raging - things got out of hand. >> well the human rights watch report says that the attack really started when a man wearing civilian clothes came through that doorway carrying a firearm and threw two tear gas canisters into this lobby, then shouted that the colectivos have arrived. then twenty more people showed up and the students set off running down that corridor. >> these students say they were holding a political meeting that

was interrupted by people with guns who chased and beat them. >> this student wanted his identity hidden for fear of reprisals. >> he says a series of colectivo attacks over the past weeks have provoked opposition students to fight back. >> but the revenge attack by opposition students is not mentioned in the human rights

watch report. to hear that story, we've come back to the neighborhood that's a colectivo stronghold. >> willians munoz is a student at the university and a member of a colectivo. he said he didn't feel safe talking to us at the university. >> one day in early april, there were protests on campus, and willians says that after clashing with the police, the opposition students turned on his group. >> ...but willians was caught. >> this is you?

>> we have an enormous risk right now. both sides has to understand right now that we need to dialogue, we need to negotiate. why? because otherwise, we are going direct to a war. >> in raids carried out before dawn, government security forces have cleared away all the student camps in the city. >> you can see the police are having stones thrown at them by the protesters. the camp was just destroyed literally a couple of hours ago. the tension's really high on the streets right now. >> there's tear gas coming! you can see the tear gas over here...watch out guys, tear gas coming down. well this is where the tents

were just yesterday. the students are furious that the camp has been broken down. >> everybody was sleeping. they were asleep. >> and who got arrested? >> all of the students. >> that's gerardo! >> yes, it's gerardo! >> he's been arrested? >> yes! he's been arrested yesterday. >> how did you get that picture? >> because on twitter... >> it looks like they're taking these barricades one by one and gradually pushing back to the area where the tents used to be set up. and the police are now advancing on this crowd. >> we're hearing some shots that sound like live rounds are now being used. it's incredibly tense on this street. >> by day's end, a policeman has been shot and killed...and hundreds more protesters detained. faced with economic troubles and the worst unrest in more than a decade, the maduro government has responded with force. ...but what we've seen and heard isn't a simple story about a dictatorship versus pro-democracy protesters.

>> the opposition movement we've met in the streets is calling for the government's downfall - and they say they're prepared to do anything it takes. but they're at odds with many venezuelans who say they'll fight to ensure the country won't return to the ways of its past. the growing polarization is made worse by the threat of outside interference, setting the stage for a simmering conflict... ...in which this could be just a shadow of what's to come in venezuela, now that hugo chavez is gone. finches

ja this is techknow, a show about innovations that can change lives. we're going to explore the intersection of hardware and humanity and we're doing it in a unique way. this is a show about science by scientists. let's check out our nerds. dr shini somara is an engineer. tonight cars learning to communicate with each other. can cars equipped with electronic smarts reduce accidents and increase safety. we hit the streets and road test this new technology. >> oh, i did not do that. dr crystal dilworth is a