Colombia's FARC guerrillas on Thursday announced that they would release a soldier they captured last week "in the coming days," calling the move a humanitarian gesture.

   The decision came in the wake of a unilateral ceasefire the leftist rebels began Saturday during peace negotiations to end Latin America's longest-running insurgency after more than 50 years.

   "Today we have launched a special humanitarian protocol for the release of Carlos Becerra Ojeda, a professional soldier captured in combat on December 19 in (southwestern) Cauca department," the FARC peace delegation said in a statement released in Havana, where negotiations to end the conflict are taking place.

   The guerrillas called the release a "new peace gesture of the FARC, a humanitarian act, considering that the soldier was slightly wounded during combat".

   "We respect the life of a combatant who is captured during combat, contrary to the army's claims," the Revolutionary Armed Forces of Colombia added.

   Becerra Ojeda was captured just hours before the FARC began its unilateral and indefinite ceasefire.

   Under the ceasefire, the FARC says its fighters will only engage in hostilities if they come under attack first.

   The FARC has declared Christmas ceasefires in each of the past two years, but this is the first without an expiration date.

   The long-running conflict has killed some 220,000 people and displaced 5.3 million more. (AFP)