Bogoya, Colombia ? The Colombian government on Wednesday blamed leftist rebels for the killing of 34 coca pickers in a spree that has stoked fears of a new wave of drug-fueled violence.

The attack, Tuesday morning in the cocaine-rich La Gabarra municipality, was the worst massacre since hard-line President Alvaro Uribe Velez took office in August 2002. He began an aggressive military offensive against Colombia’s armed outlaws and kicked off peace talks with right-wing paramilitary death squads.

The government blamed the massacre on rebels. “It’s the FARC, once again,” Defense Minister Jorge Alberto Uribe told reporters, citing accounts from a handful of survivors and referring to Latin America’s oldest and largest rebel army, the Revolutionary Armed Forces of Colombia.

Both the rebels and their paramilitary foes fill their war chests with drug profits. Local police officials said Tuesday’s massacre likely was the result of a rebel offensive aimed at wresting the cocaine crops along the lush and lawless border with Venezuela from paramilitary control.

“Coca is still fueling the conflict. As long as coca exists, this will continue,” said Camilo Matiz, a spokesman for the government’s Social Solidarity Network that offers shelter, food and workshops to victims of Colombia’s 40-year civil conflict. “It’s lamentable,” he said of the attack. “We thought we’d got over this stage.”