Colombia's FARC Kills 5 Soldiers on Eve of Truce

Colombia's FARC guerrillas killed five soldiers Friday in an attack that came on the eve of a unilateral ceasefire hailed as a key step in peace negotiations, the army said.

FARC fighters ambushed a patrol in the rural area of Santander de Quilichao in western Colombia, an attack that also left five wounded, said a military source speaking on condition of anonymity.

The Colombian government's chief negotiator in the peace talks with the FARC, Humberto de la Calle, condemned the attack.

"We have to reiterate that the purpose of the talks is for this to stop," he said.

The incident came a day before the leftist guerrilla group was due to begin an indefinite, unilateral ceasefire that it declared on Wednesday, a move the European Union and United Nations had praised as a positive step to accelerate the talks aimed at ending the 50-year-old conflict.

The FARC had said that starting Saturday they would only engage in hostilities if they came under attack.

On Thursday, Colombian President Juan Manuel Santos called the gesture a "gift... full of thorns" and again rejected the rebels' longstanding demand for a bilateral ceasefire, which he says they would use to regroup.

The two-year-old peace talks in Cuba, the most promising effort yet to end the conflict, have encountered rocky terrain in recent weeks.

Last month the FARC captured an army general, their highest-ranking captive ever, defending the act as a legitimate act of war in the absence of a ceasefire.

They released him on November 30 in order to revive the peace process.