Nigeria's main militant group is threatening new attacks, this time against oil and fuel storage facilities.
In a statement Tuesday, the Movement for the Emancipation of the Niger Delta (MEND) warned people living near fuel depots to evacuate immediately.
The group also said it will target vehicles transporting petroleum products.
MEND said it was protesting the arrest and detention of fellow militants.
The Nigerian government has carried out a series of raids and attacks on militant camps in the oil-rich Niger Delta.
Militants and gangs have attacked oil facilities in the region for years, reducing Nigeria's oil production.
Many militants surrendered their weapons in 2009 under a government amnesty program. But factions of MEND have continued to fight, saying they want a more equitable distribution of oil wealth in the region.