The Colombian government's peace commissioner, Victor Ricardo, and guerrilla leaders held talks on Friday in a bid to move the peace process forward.

Mr Ricardo met Manuel Marulanda, the head of the Revolutionary Armed Forces of Colombia, in a demilitarised zone.

They discussed the exchange of some three-hundred soldiers and police for four-hundred jailed guerrillas.

On his return to Bogota, Mr Ricardo said another meeting was planned, but he gave no indication of a breakthrough, saying only that he had told the rebels that any prisoner swap would have to take place within the framework of the constitution and the law.