The Congolese army clashed with a local militia in Central Kasai province on Friday, killing 14 militiamen, officials said.
The army was responding to an attack by the Mouvement Politico-Coutumier, which had looted and torched administrative buildings in the city of Kena-Nkuna, said Alex Kande, governor of the province.
About 50 people have been killed since August in attacks by the Mouvement Politico-Coutumier, a new armed group targeting army installations and symbols of the state. During one of the attacks, the militia controlled the airport of the provincial capital Kananga for several hours.
The armed group was created by a local chief opposing central government powers, who was killed during clashes with the army in August.
Central Congo had until now been generally peaceful, as opposed to the east of the country, where dozens of armed groups vie for control over territory and mineral resources.