Nigerian militant group Niger Delta Avengers (NDA) said on Nov. 15 that it attacked the Nembe Creek Trunk Line pipeline in the southern Niger Delta in a blow to the government's efforts to quell militancy in the region.

The group, which in August said it would halt hostilities to pursue talks with the government, said on Nov 13 that it had resumed attacks because of the continued presence of the army in the region.

The NDA, which wants more energy wealth to go to the swampland region that is the source of most of Nigeria's oil, said on its website that its strike team attacked the Nembe 1, 2 and 3 branches of the pipeline.

On Nov. 1, Nigeria's president met leaders from the region for the first time since the attacks began. They gave him a list of 16 demands including the withdrawal of the army from the region, ordering oil firms to move their headquarters there and spending more on development.

"We are determined to continue this war by all means necessary, until that environment prevails for a genuine dialogue and negotiations within the framework of the 16-point key demands presented," NDA spokesman Mudoch Agbinibo said in a statement posted on the group's website on Nov. 15.

But the military said troops stationed at Nembe Creek "repelled saboteurs who tried to vandalize and steal a control unit" from a wellhead. A spokesman said attackers who targeted the Nembe Creek pipeline on Nov. 14 had been thwarted.

"Vandals abandoned their tools on sighting troops," military spokesman Olaolu Daudu said.

Reuters was unable to immediately verify details of the attack.

Aiteo is the operator of the Nembe Creek Trunk Line, although Agip, the local branch of Italy's Eni, owns portions of the pipeline, as does Oando. The pipeline is 100 kilometers long and has a capacity of 600,000 barrels per day.

An Eni spokesman said the company was looking into the claims.

Royal Dutch Shell Plc (NYSE: RDS.A), which operates the Bonny Light crude oil that flows to the export terminal through the pipeline, divested its stakes in the pipeline in 2015.

A Shell spokeswoman said the company had not declared force majeur on Bonny crude.

A spate of attacks by a number of groups -- the most active of which has been the NDA -- began in January and cut OPEC member Nigeria's crude production by more than one-third in the summer. Crude oil sales generate 70% of government revenue.

With attacks becoming less frequent in the last few months, the oil minister in November said output had recovered to 2.1 million barrels a day, bringing it roughly back to levels before the attacks began.