Six Dead in Terrorist Attack in Nigeria's South: Army

Lagos: Six people were killed when terrorists attacked a boat belonging to Nigeria's state-run oil firm, the army has said, 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 2016, denied involvement but claimed a separate strike and vowed to bring crude output to a halt.

"During the deliberate attack two soldiers were killed, one wounded, one soldier missing while four civilian staff attached to the house boat were shot dead," army spokesman Captain Jonah Unuakhalu said in a statement on Thursday.

No specific group was mentioned as being responsible and Unuakhalu said only "suspected terrorists... disguised as ordinary commuters" in five speedboats carried out the attack. But the Niger Delta Avengers quickly said it was not involved.

"Killing of sleeping soldiers is not our style," it said in an email. "We promise the world that in this process of liberating our people, not a single blood of Nigeria soldiers will be wasted despite the provocation... "Our war is on oil installations not to take innocent lives," it said.

The group earlier this week, however, warned it would step up its campaign with violence against facilities and personnel.

"To the international oil companies and indigenous oil companies, it's going to be bloody this time around," it said in an email and a statement on its website on Monday.

The group, whose targets have included oil majors such as Shell, Chevron, Eni and the NNPC, earlier claimed another attack.

"At about 2:00 am today @NDAvengers blew up the Ogboinbiri to Tebidaba and Clough Creek to Tebidaba Crude Oil pipelines in Bayelsa State," according to its Twitter account.

"This is in line with our promise to all international oil companies and indigenous oil companies that Nigeria oil production will be zero," it added.

Nigeria's defence spokesman Rabe Abubakar confirmed the attack without giving further details, but said they were aware of those behind the group.