By Daniel Wallis and Diego Ore
CARACAS, March 31 (Reuters) - After her bus was stopped at a barricade set up by protesters in Venezuela one night last week, a pregnant 28-year-old got off to walk home in the dark.
Adriana Urquiola, who worked as a sign language interpreter at a TV station, was returning from a shopping trip. Moments later, she was shot several times and died.
Witnesses say she was hit by a man who got out of a black SUV at the barrier and opened fire with a pistol. But the exact circumstances are unclear and that is often the case when trying to identify the killers in Venezuela's worst unrest in a decade.
Both sides blame the other in many of the roughly three-dozen deaths, and each suspects hardliners among their rivals of morbidly desiring a higher toll for political reasons.
The government accuses the opposition of wanting more fatalities to make their case of state-sponsored violence against peaceful rallies and justify international sanctions against members of President Nicolas Maduro's administration.
The opposition says the government wants a higher toll as it blames the chaos on opposition gunmen and hooded demonstrators blocking roads, and to distract from the issues that started the protests, such as high inflation, food shortages and crime.
The drip-drip of new fatalities, and fierce disagreements about what caused them, are driving the political debate and are being used by both sides to rally supporters.
In a country with at least 15,000 homicides last year, there is ample scope for confusion and propaganda. Many of the deaths occurred in chaotic circumstances, often after dark, amid clashes between opposition protesters on one side and pro-government militants or National Guard troops on the other.
"Each and every fatality is the fault of the crazy 'guarimberos'," Maduro said last week, using the local term for demonstrators who barricade streets.
There is little agreement even on how many deaths can be attributed to the turmoil, which began with student protests and intensified when three people were shot dead after a Feb. 12 opposition rally in downtown Caracas. ( )
The government says 39 people have died while the opposition says the toll is 28. More than 550 people have been injured.
The dead include supporters of both camps and members of the security forces. Prosecutors have accused at least 20 people in connection with the deaths, but in most cases have not released enough details to verify who is responsible.
Few details are universally agreed on in any of the other cases. Both sides' lists show that at least 18 victims were killed by unidentified gunmen, although they blame their foes.
The government says 10 people were killed while trying to get through or dismantle barricades, many of them felled by gunshots that it blames - without definitive proof - on armed opposition hardliners wanting to keep the barriers in place.
Also without compelling evidence, opponents blame bands of pro-Maduro militants on motorcycles for opening fire on protesters.
And the government includes among victims of the protests two elderly women who died because the ambulances taking them to hospitals for emergency treatment were held up in traffic gridlock caused by protesters' barricades.
Confusing matters further, both sides accuse each other of sending disguised troublemakers to infiltrate their ranks.
Prosecutors have attributed five deaths to members of the security forces and 17 are under arrest for crimes including brutality, torture and murder.
Eight members of the forces have been killed, all but one of whom were National Guard troops shot while taking down barriers, according to the government.
Eight of the dead appear to be reliably identified as opposition supporters, and five as pro-government. In the other cases, the victims' political affiliations are in dispute and hard to prove.
The murder of Urquiola - the recently married, pregnant woman killed after stepping off the bus in Guaicaipuro on the outskirts of Caracas - is among the most-fiercely debated.
Urquiola and another woman were shot by a suspect who got out of a black SUV, opposition leader Henrique Capriles said that night, stressing that her death was not linked to protests.
Some local media said the gunman was a convicted kidnapper who found the barricade blocking his way home. They said he fired 17 rounds in the attack, and has since fled the country.
In a phone call to a newspaper, a man admitted killing Urquiola in panic after being shot at himself and having his car pelted with bottles and stones by hooded protesters as he drove up to the barrier.
The next morning, the municipality's pro-government mayor blamed her death squarely on the demonstrators who blocked the street, and declared three days of mourning.
Capriles accused Maduro's government of being content to watch the death toll rise, because it distracted people from the country's economic and political crisis.
"The violence only suits one side," he said.
Another much-discussed death was that of Jimmy Vargas, a 34-year-old who fell from a roof during clashes in the western city of San Cristobal.
Some witnesses said a teargas cannister or buckshot fired by the National Guard hit him first, but prosecutors say there is no proof of that and a cellphone video of the incident shows him appear to stumble and then plunge backward while climbing down from a ledge.
One of the most controversial - and still somewhat mysterious - deaths was either the first, or the second.
Juan Montoya, a pro-government militant, was among a group of bikers who turned up in the center of Caracas on Feb. 12 just as masked, stone-throwing demonstrators broke away from a peaceful opposition rally to clash with riot police.
Amid the fighting and swirling teargas, videos show several members of the Sebin national intelligence agency arriving on the scene. Two are seen firing pistols towards the melee.
Montoya, 40, was killed, as was Bassil Da Costa, a 24-year-old carpenter who was at the protest with his student cousin.
While a top Socialist Party official initially blamed both deaths on "fascist" foes seeking to topple Maduro, authorities later arrested five Sebin agents in connection with both deaths. (Additional reporting by Brian Ellsworth; Editing by Andrew Cawthorne, Kieran Murray and Sandra Maler)