Six Colombian police officers have been killed while on patrol in the south-west of the country in an ambush blamed on left-wing rebels, officials say.
The officers were shot dead in Cauca province by suspected FARC guerrillas, local police said.
The killings come as the Colombian government and the FARC prepare for the next stage in peace talks, due to get under way next week in Cuba.
The talks began earlier this month in Norway but there has been no ceasefire.
President Juan Manuel Santos has said he wants to avoid the mistake of the previous peace talks in the late 1990s, when the rebels were given control of a vast demilitarzsed zone and used the opportunity to regroup.
The latest peace attempt, the first direct contact in a decade, was formally launched in Oslo on 18 October.
The two sides are due to hold preparatory meetings in Havana next week, with the negotiations proper beginning on 15 November.
The talks are due to focus on five key areas: the end of armed conflict; land reform; guarantees for the exercise of political opposition and citizen participation; drug trafficking; and the rights of the victims of the conflict.
The number of FARC combatants is now believed to be some 8,000, down from 16,000 a decade ago.