Six dead in attack in Nigeria's south - report

Six people have been killed after militants attacked a boat belonging to Nigeria's state-run oil firm, the army says in the latest violence to hit the country's increasingly restive oil-producing region.

The Niger Delta Avengers group, which has been attacking pipelines and facilities since early this year, denied involvement but claimed a separate strike and vowed to bring crude output to a halt.

The deadly attack on the Nigerian National Petroleum Corporation (NNPC) boat happened in the Warri area of Delta state, which has seen a spate of attacks recently.

No specific group was mentioned as being responsible and only "suspected militants... disguised as ordinary commuters" in five speedboats carried out the attack.