Two suspected FARC fighters were killed in combat in northern Colombia on Wednesday, four days after the government announced a revised peace accord with the rebel group.

"Fighting took place in the south of the Bolivar department, and guerrillas who claimed to belong to the FARC were killed," the government's chief peace negotiator Humberto de la Calle told Caracol television.

The army confirmed the report of fighting which comes in violation of a bilateral ceasefire in place since August.