The deaths prompted hundreds of thousands of people to take to the streets last week in protest against kidnappings by guerrilla forces.

Security guarantees

"We got a request from the Farc to recover the bodies and we got the green light from the government to do so," Yves Heller, spokesman for the International Committee of the Red Cross in Colombia, said.

"We don't how long it will take to get the security guarantees we need to go in and get the bodies."

Colombia was stunned in 2002 when 12 politicians were kidnapped from a government building in the western city of Cali by Farc fighters posing as soldiers, escorting them onto a bus after saying they were being evacuated due to a bomb scare.

The politicians were among dozens of high-profile hostages Alvaro Uribe, the Colombian president, wanted to exchange for guerrillas held in government jails.

Farc commander convicted

Meanwhile, as senior commander of the Colombian rebel group has been convicted in the United States of helping to hold three Americans in a jungle prison camp for years.

Ricardo Palmera, centre, was extradited
to the United States in 2004 [EPA]
Ricardo Palmera, who is better known by the pseudonym, Simon Trinidad, was extradited to the US in 2004 to face hostage-taking and terrorism charges.

On Monday, jurors found Palmera guilty of conspiracy to commit hostage-taking, they were split over whether to convict him of supporting terrorism.

A federal judge sent them back to keep deliberating that charge and three counts of actual hostage-taking.

The three Americans - Marc Gonsalves, Thomas Howes and Keith Stansell - were civilian Pentagon contractors flying a surveillance mission over the Colombian jungle when their plane crashed in 2002.

Palmera denied ever seeing the three men but acknowledged serving as a negotiator in an attempt to arrange a prisoner swap.