The National Liberation Army (ELN), which is in peace negotiations with Colombia's new leftist government, said in a video on social media that the truce would last from Christmas Eve to January 2.

It would apply "only to the military and police forces," a masked ELN member said, adding "we deserve the right to defend ourselves in case of being attacked."

Just last week, some 10,000 inhabitants of Colombia's northwestern Choco jungle region found themselves trapped as the ELN launched an armed strike.

The attack, criticized by the government and opposition, was said by the ELN to be in retaliation for the death of one of its own at the hands of "paramilitaries" allegedly in "collusion" with government forces.

Colombia has suffered more than half a century of armed conflict between the state and various groups of left-wing guerrillas, right-wing paramilitaries and drug traffickers.

The ELN is the last recognized rebel group operating in Colombia, although dissidents who refused to sign the 2016 peace deal between the FARC guerrilla group and the government also remain active.

Colombian President Gustavo Petro -- a former urban guerrilla himself -- has vowed to negotiate with armed groups in search of a "total peace" for Colombia.

Talks resumed with the ELN in Venezuela last month for the first time since 2019 -- when Petro's conservative predecessor Ivan Duque broke off negotiations following a car bomb attack on a police academy that left 22 people dead.

The initial talks have not resulted in a formal ceasefire agreement.

Armed since 1964, the ELN has a force of some 2,500 fighters and a wide network of collaborators, according to independent estimates.