Nigeria's president on Sunday said he would hold talks with leaders in the oil-producing Delta region to address their grievances in a bid to stop a surge in pipeline attacks, but that an army crackdown would continue.
People in the southern Delta region, where oil giants such as Royal Dutch Shell and Chevron operate, have for years complained about the oil industry's pollution and of economic marginalisation by the state.
Some have taken up arms and a recent surge in attacks on oil installations has cut Nigeria's oil output to a 20-year low.
"The recent spate of attacks by militants disrupting oil and power installations will not distract us from engaging leaders in the region in addressing Niger Delta problems," President Muhammadu Buhari said in a televised speech marking his first year in office.
Buhari said the government was committed to a clean-up of polluted areas.
"I believe the way forward is to take a sustainable approach to address the issues that affect the Delta communities."
Local officials and Western allies such as Britain have told Buhari that moving in troops to the Niger Delta would not be enough to stop the attacks and that the population's grievances would have to be dealt with.
Security operations would go on, Buhari said in his speech. "We shall apprehend the perpetrators and their sponsors and bring them to justice."
But as his address was being broadcast, residents in the Delta village of Oporoza, home of a former militant leader, said the army had raided their community and was not allowing the evacuation of any wounded.
"No person is allowed to move in and out of Oporoza," said the Ijaw Youth Council, which represents the largest ethnic group in the region. "A 40-horse power speed boat which came to rescue residents in serious medical condition was seriously attacked by the military."
In its own statement, the army said it had exchanged gun fire with a militants attacking a crude pipeline run by Italy's ENI, hours after a group called Niger Delta Avengers militants claimed another strike against oil facilities.
The army's statement did not mention Oporoza.
Apart from the militant attacks in the Delta, Nigeria's oil revenues have also been hit by a slump in oil prices, leaving Africa's largest economy in crisis.
On Thursday, Oil Minister Emmanuel Ibe Kachikwu said an amnesty programme for former militants, signed in 2009 to end a previous insurgency, needed to improve.
The scheme providing cash benefits and job training to those who lay down their arms has had its funding cut by two thirds. Buhari has also upset former militants by ending contracts to protect pipelines, part of a drive to tackle graft.