Ecuador's President Rafael Correa warned Monday that reports U.S. intelligence played a role in a 2008 Colombian attack on FARC rebels in his country as a threat to regional peace efforts.

Over the weekend, the Washington Post reported that a secret Central Intelligence Agency program had helped Colombia kill at least two dozen leftist guerrilla leaders.

Colombia's battle against leftist FARC guerrillas has been secretly aided by a U.S. intelligence program that helped government forces hunt down and assassinate rebel leaders, the Washington Post reported Sunday.

The secret CIA program -- separate from the $9 billion U.S. aid package dubbed Plan Colombia, which launched in 2000 -- was initially authorized by president George W. Bush around the same time.

Negotiators concluded the year's last round of Colombian peace talks Friday with the chief government representative praising the progress made as "important and hopeful."

"Never before have we advanced so much in terms of agreements with the FARC as we have on this occasion," said Humberto de la Calle, the lead government negotiator.

The Colombian army said Wednesday five FARC guerrillas were killed during a military operation, days after the rebel force declared a unilateral ceasefire.

The dead included the leader of a FARC unit, Arnulfo Suarez Gonzalez, known as Alberto Guevara, who the army said was engaged in drug trafficking.

A leftist guerrilla linked to high profile kidnappings and an attempt to assassinate a former Colombian interior minister has been killed, police said Monday.

News of Diego Tabares' death came as the FARC was initiating a unilateral ceasefire, its second since the start of peace talks in Havana in November 2012.

Colombia's FARC rebels begin a 30-day unilateral ceasefire Sunday as peace talks continue with the government to try to end Latin America's longest insurgency.

The Revolutionary Armed Forces of Colombia (FARC) asked its units to "cease fire and hostilities for 30 days" from December 15 in a message last week from Havana where the talks are being held.

Colombia's FARC rebels declared a 30-day unilateral ceasefire on Sunday and urged the government to do the same in the wake of a deadly bombing blamed on the guerillas.

The announcement, effective December 15, came in a statement issued in the Cuban capital where the FARC and Bogota are in talks to end their decades-long conflict.

Eight people were killed Saturday in a bombing in Colombia which was immediately blamed on leftist FARC rebels who are currently engaged in peace talks with the government.

The victims comprised two civilians and six members of the military and police, who died when a vehicle loaded with explosives blew up in the small town of Inza as locals prepared for a farmer's market, authorities said.

President Juan Manuel Santos on Tuesday said Colombia and the United States would triple security cooperation in a group of third countries in Latin America and the Caribbean.

Santos, after meeting President Barack Obama at the White House, also proposed an economic cooperation pact in Latin America based on the Alliance for Progress unveiled by president John Kennedy in Colombia 50 years ago.

Colombia's FARC guerrilla group Monday called on the government of Juan Manuel Santos to decriminalize coca growing and drug use, in peace talks in Havana.

FARC negotiator Pablo Catatumbo made the proposal before the day's talks, which are centered on drug trafficking, resumed.