BOGOTÁ, Colombia — Venezuela is waging its most concerted military campaign in years, targeting what it says is a criminal group operating within its border near Colombia but also sending an estimated 5,000 of its own civilians fleeing into the neighboring country.
The assault — which began with several days of airstrikes that security experts described as Venezuela’s largest use of firepower in decades — represents a significant departure from the largely hands-off approach it has long employed toward the illicit organizations that flourish along its border.
For years, officials in President Nicolás Maduro’s government have tolerated and sometimes even cooperated with these armed groups, many of them with roots in Colombia, as they moved drugs and other contraband between nations.
Now it has lashed out at one of them, though the reasons remain murky. Mr. Maduro has claimed in recent days that the attack reflects his government’s policy of “zero tolerance toward irregular Colombian armed groups.”
Analysts cast skepticism on the official explanation.
“We’ve never seen something like this on this scale,” Kyle Johnson, founder of Conflict Responses, a Bogotá-based nonprofit focused on security issues, said of the fighting.
The military campaign began March 21 in Apure, one of the country’s poorest states, and has led to the deaths of at least nine people whom the Venezuelan government considers to be guerrillas and two of its own personnel, the defense minister, Vladimir Padrino, said.
Several Colombian rebel groups have operated in Venezuelan territory in recent years, including dissident members of the Revolutionary Armed Forces of Colombia who have refused to lay down their weapons following a 2016 peace deal.
The Venezuelan assault, centered around La Victoria, a town of about 10,000, has been aimed at a faction of FARC dissidents known as the Tenth Front, according to local residents, leading security experts to suggest they may have broken unwritten rules laid out by the Maduro government or its allies.
The airstrikes that kicked off the campaign have been followed by ground fighting between the Venezuelan military and the Tenth Front that “has escalated every day,” said Juan Francisco García of the Venezuelan human rights group Fundaredes, which has an extensive communication network in the region.
He described “a civilian population trapped between warring groups.”
In interviews, witnesses in and around La Victoria described waking up on Sunday, March 21, to the rumble of government trucks passing through town, followed by the roar of low-flying planes.
“It was still dark when I began to hear the trucks,” said Miguel Antonio Villegas, 66, the chief spokesman for the community council in La Victoria, who saw the military convoy through his window. Soon he said, “the bombs began.”
As the villagers awoke, Mr. Villegas said, they gathered outside and saw explosions just to the east.
In the following days, Mr. Villegas said, bombing continued in the area near La Victoria, and soldiers began to pour into town, interrogating civilians and entering their homes, accusing them of collaborating with the guerrillas.
The FARC dissidents apparently responded. Two days after Venezuela’s military campaign began, a bomb exploded at the tax office and the town lost power in an attack that Fundaredes attributed to the FARC group.
By the next day, bombing from government planes was so close to La Victoria that “even the floor moved,” said Mr. Villegas. Terrified, he stuffed a backpack with belongings and fled with two family members to the bank of the narrow river that separates La Victoria from the Colombian town of Arauquita.
The bank was packed with neighbors who were also fleeing, said Mr. Villegas, who used a small boat to cross over to Colombia, where he and his family remain.
The military has since stepped up its presence in La Victoria, according to a civilian witness who asked not to be named, fearing retribution from Venezuelan security forces.
The man, the owner of a small market, described soldiers rounding villagers up, demanding identification, pinning them against walls and pointing weapons at them. In one instance, he said, a resident was forced to kneel and was then beaten and detained.
One man who spoke with a Human Rights Watch researcher said that four members of his family — his mother, father, brother and uncle — had been killed by Venezuelan security forces, which accused the family of being guerrillas, the group said. At least eleven civilians, said the researcher, had been detained by Venezuelan security forces.
The Venezuelan government has assigned two prosecutors to investigate accusations of human rights abuses, the country’s attorney general, Tarek Saab, said. But the government has also sought to limit news coverage of the military campaign, according to Fundaredes.
On Wednesday in La Victoria, Venezuelan authorities detained two journalists with the Venezuelan channel NTN24 and two human rights activists with Fundaredes who had been trying to document the crisis. They were kept for a day before being released, according to family members and friends.
Tamara Taraciuk Broner, Americas deputy director at Human Rights Watch, called abuses documented by her organization as “a case study in the atrocities that the regime has been carrying out, and continues to carry out, with impunity.”
She continued: “This should be a wake up call for the International Criminal Court, which has the duty and the power to criminally investigate those who are ultimately responsible for the most heinous international crimes.”
Isayen Herrera in Caracas contributed reporting.