Documentary : Town Toughs It Out Amid Goon Squads and Guerrillas : In this violent Colombian oil center, bombings and murders are daily occurrences.

The explosions created three heavy pulses of sound on a horizon suddenly aglow with light.

They were enough to momentarily confuse a visiting reporter but not residents of Barrancabermeja, who recognized the telltale signs of terror. For them, the sudden light and vibration signaled that leftist guerrillas were again at work on the city’s outskirts. They also portended bloody retaliation by enraged right-wing death squads.

While a reporter raced with colleagues through the darkness of a power outage to scenes of burning destruction, most residents stayed put. They didn’t need to see the towering columns of flame and smoke to realize that guerrillas had once again bombed pipelines around this city of 157,000, a center of Colombia’s oil industry. They didn’t want to wander darkened streets, just as they would never choose to swim in a black stream that might be infested with piranhas.

They sensed correctly that retaliation for the guerrilla action would come in darkness and that civilians would be the target.

Residents knew all of this from experience. Barrancabermeja’s population had already taken the brunt of months of violence between the last active Cuban-inspired insurgency in the West and right-wing killers trying to extinguish it. The conflict has propelled Barrancabermeja to second place on the list of Colombia’s most homicidal cities, per capita (the leader remains Medellin, center of the cocaine trade).

In January and February alone, 85 people were killed here, a rate surpassing last year’s record average of one murder per day. More than half of the victims fell in the poorer eastern neighborhoods, where two largely rural-based guerrilla groups--the Revolutionary Armed Forces of Colombia (FARC) and the National Liberation Army (ELN)--have their greatest urban support in this country.

The petroleum-rich region around Barrancabermeja has been a center of the guerrilla insurgency since its beginnings in the 1960s. Rebels found they could finance their activities by extorting money from foreign petroleum companies and by kidnaping and holding their engineers for ransom.

The violence was raised a notch in the early 1970s when right-wing death squads began forming in the countryside to fight the rebels by murdering civilians suspected of supporting them. Over the years, the civilian death toll mounted as the the army randomly attacked rebel bases with helicopter gunships and fighter planes.

This growing insecurity in the countryside caused an exodus of thousands of peasants to the city in recent years. But the peasants haven’t escaped the violence.

The leftist guerrillas, taking advantage of the growing poverty in Barrancabermeja, have established urban fronts. In marginal neighborhoods, where open sewers and a lack of water and other services are the norm, guerrillas have filled the vacuum caused by the government’s inattention to social problems. Rebels now even act as a sort of police force, executing suspected criminals.

“The guerrillas have the people’s sympathy, not because of any political project but because they are the only force of order here,” said one resident too frightened to give his name.

To counter the rebel’s urban presence, the first right-wing death squads appeared in Barrancabermeja last August. The death squads, often with support of members of the government security forces, are increasingly challenging rebel authority through slayings in the city. Three such massacres this year have left 18 people dead.

In Barrancabermeja, the fear of becoming the conflict’s next victim is as palpable as the viciously blazing sun that often sends temperatures over 100 degrees. In the office of the president of a regional human rights committee, a droning air conditioner tempered the heat, but there was still the sense of dread.

“The (rebels’) bombings will likely lead to more violence against civilians,” said Jorge Gomez the day after the oil pipeline blasts, the worst guerrilla action here in recent history. “There is a possibility that three to five people will be killed shortly in retaliation.”

Prophesying doom in Barrancabermeja is like predicting rain when the sky is black with clouds. And many, including Gomez, know what it’s like to be caught in a downpour of violence.

Though the 43-year-old activist had recently traveled to the United States to receive the Letelier-Moffit Human Rights Award (sponsored by the Washington-based Institute for Policy Studies), once back in Barrancabermeja, he found international recognition an intangible ally at best. It was maybe useful in making enemies think twice before marching into his unguarded office, but not at all helpful at stopping them once they did. For that, there was a loaded pistol. It appeared nestled in a seat cushion every time Gomez rose from his chair.

On his desk was a copy of a death-squad flyer that began circulating last year in Barrancabermeja. The sheet announced the beginning of an extermination campaign against rebel “sympathizers, combatants, activists and collaborators” and specifically threatened Gomez and other workers in the human rights office, calling it a front for the ELN.

The seriousness of the threat became apparent Jan. 29, when Blanca Valero de Duran, Gomez’s secretary, was gunned down by a lone hit man just half a block from a manned police post. Gomez said she was just another victim crushed by the extreme right and left.

“The guerrillas say they must enter the neighborhoods to protect people from the death squads,” he said. “It’s a very grave situation because civilians are caught between these two deadly forces.”

In the eastern neighborhoods, the situation had moved beyond grave to critical as a result of guerrilla bombings of oil and gas pipelines around the country’s biggest petroleum refinery.

A commander of one of the guerrillas’ urban fronts, known as milicias , said that on-again, off-again peace talks between the government and rebels mean nothing to the people of Barrancabermeja.

“Our job is to prepare these people for war,” said the ELN commander, known as Pompilio. The ELN seemed to be doing a good job since the walls of the tin-roofed shack where he sat were covered with children’s drawings of machine guns and helicopters.

“The people of this neighborhood know there will be great repression as the result of last night’s attack (on the pipelines). We are telling them to resist the aggression.”

A similar mood was prevalent in another neighborhood, where two FARC commanders only occasionally flashed glances at reporters sitting with them on a store’s flimsy wooden porch. Their eyes instead followed an army helicopter circling above the city.

Both commanders accused the military of a willingness to gun down as many civilians as necessary to kill just one rebel.

“We and the army are two military forces that should confront each other, but troops enter these neighborhoods and spray machine-gun fire on the civilian population,” one said. He admitted that guerrillas also killed civilians suspected of being army informants in so-called “adjustments.”

“We investigate a person thoroughly first to make sure he is an informer, and if so, we make the necessary adjustment,” the commander said calmly.

Paranoia is not confined to the city’s extreme left. Barrancabermeja’s police commander, Maj. Jaime Orosco, articulated his own version of enemy infiltration, saying guerrillas have representatives in every major sector of Colombian society except the military.

“Barrancabermeja is surrounded by the rebels, and the only thing preventing them from taking power are public security forces,” he said, staring intensely at reporters seated in front of his colossal desk. “We are the only state organism here that is still pure.”

He, too, had put his forces on alert in anticipation of more violence. Soldiers and police were patrolling the streets as workers tried to put out the pipeline fires on the edge of town. Residents of the poorer neighborhoods were preparing to shut themselves inside their small shacks to wait out the night. All of Barrancabermeja appeared poised for the inevitable.

That night, two reporters and a photographer were eating at a restaurant near the river docks, an area where dirt from the streets eddies into the dim doorways of pool halls and houses of prostitution. The concrete buildings, in turn, pour salsa music from battered Kennedy-era jukeboxes back into the dusty current of the street.

In the restaurant, plates of fried catfish had just clattered down on the chipped Formica table when the lights in the zone went out. Another electricity failure.

“I’ll meet you guys under the table,” one reporter said to the others. Nobody else said a word--not in the restaurant, not on the suddenly silent street.

The following night in a similarly impoverished neighborhood, unidentified gunmen took advantage of another power failure to indiscriminately fire on a bar filled with civilians. When the lights came back on, they illuminated five more bodies in Barrancabermeja.