The Colombian defence minister, Rodrigo Lloreda, has rejected a demand by the Revolutionary Armed Forces of Colombia FARC that the government should withdraw its remaining troops from a demilitarised zone set up to promote peace talks.

Mr Lloreda said there were only one-hundred soldiers in the area compared with some two-thousand guerrillas.

For their part, the rebels have accused the government of failing to keep its word.

Correspondents say the latest developments indicate the difficulties surrounding the peace process.

Representatives from the two sides were to have met on Monday to discuss exchanging prisoners, but the meeting was postponed when members of the judicial system refused to take part.