Colombia accuses FARC of 'war crime' in disputed clash

Colombia's attorney general accused the FARC rebels Thursday of committing a war crime by ambushing a resting army unit with unconventional weapons, but the guerrillas insisted they acted in self-defense.

The night-time clash Tuesday-Wednesday in the western rebel bastion of Cauca left 11 soldiers and two FARC fighters dead, according to the army -- the latest setback for the two-year-old peace process aimed at ending Colombia's five-decade conflict.

The talks, which have reached partial deals on several issues, continued Wednesday and Thursday despite the violence.

In the aftermath of the incident, President Juan Manuel Santos ordered the resumption of air strikes on FARC positions, accusing the Marxist rebels of breaking the unilateral ceasefire they declared last December.

FARC commander Pablo Catatumbo rejected the army's description of the incident as a rebel attack, calling it a "military confrontation" in which the rebels acted defensively.

But Attorney General Eduardo Montealegre said investigations showed the FARC was solely responsible.

"The attack was a late-night ambush carried out when the soldiers were resting," he said.

"The methods of attack used by the FARC, which included the use of unconventional explosive devices, constitute a war crime, in addition to the homicides that were committed."

He said attacking soldiers outside combat was also a violation of international humanitarian law.

Forensic experts found that explosive devices, assault rifles and in one case a handgun were used, "characteristics that correspond with the scenario of an ambush," they said.

"We have found no evidence indicating that (the soldiers killed) were able to react to the attack," chief forensic analyst Carlos Valdes told journalists.

The incident was one of the deadliest since peace talks between the government and the FARC opened in Cuba in November 2012.

Some 20 soldiers were also wounded.

Speaking in Havana, Catatumbo, who used to lead the guerrilla units involved, blamed the government.

"There was a military confrontation caused by an army seige, which is not new. This operation against these units has been going on for four months," he told a press conference.

He called on Santos to reverse his decision to renew air strikes, which the president had suspended on March 10 in recognition of the guerrillas' ceasefire.

"The solution is not to start bombing again. Please, they've been bombing in Colombia since the war began and it's only accomplished one thing: to increase the number of dead," he said.

The government has refused to commit to a bilateral ceasefire until there is a final peace accord.

The Colombian conflict has killed more than 200,000 people and uprooted five million since the Revolutionary Armed Forces of Colombia was founded in 1964.