A unit of Colombia's FARC rebel group says it won't lay down its arms, despite a recently signed peace deal with the government. President Santos has warned anyone who fails to get on board will end up dead or in prison.

The announcement from the influential Armandos Rios First Front rebel unit came less than two weeks after leaders of the Revolutionary Armed Forces of Colombia (FARC) and the government agreed to a ceasefire plan.

"We have decided not to demobilize, we will continue the fight for the taking of power by the people for the people, independent of the decision taken by the rest of the members of the organization," the unit said in a statement. The move is the first public sign of opposition to the accord within rebel ranks.

The 200-strong front, based in the southeastern jungle province of Guaviare, said it objected to the truce, arguing it did not resolve the social and economic problems that had prompted FARC to take up arms in the first place.

The Marxist guerrilla group has been waging an insurgency in Colombia since 1964. More than 220,000 people have been killed and millions displaced in what has become Latin America's longest running armed conflict.

Peace deal under threat?

The Armandos Rios First Front, which famously took ex-presidential candidate Ingrid Betancourt and three American contractors hostage, also said it would respect fellow rebels who chose to hand in their weapons.

"We invite all guerrillas and militia who are not in agreement with demobilization and the laying down of FARC weapons to join forces and continue united as an organization," its statement said.

There was no immediate response from FARC leaders, who last month signed a historic bilateral ceasefire with Colombian President Juan Manuel Santos. The agreement stipulated that rebels have 180 days to begin laying down their arms.

Santos had expressed hope that peace talks, which have been taking place in Cuba since 2012, could wrap up as early as this month. But following the statement from the Armandos Rios First Front he warned the group would face consequences if it did not accept the ceasefire.

"Anyone with doubts, best leave them aside and join the peace accord, because it's the last opportunity they will have to change their lives, because otherwise they will end up, I assure you, in a grave or in jail," he said.

(DW)