Nigeria's main militant group in the Niger Delta says it will resume attacks on oil facilities, three months after calling a cease-fire. The Movement for the Emancipation of the Niger Delta (MEND) was responsible for some of the region's biggest attacks in recent years.
MEND rebels warned oil companies to withdraw from the Niger Delta ahead of "an all-out onslaught" against them.
The group said it had become disillusioned by the government's inability to sustain the peace process. The prolonged absence of President Umaru Yar'Adua, who has been receiving treatment for a heart ailment in Saudi Arabia since November, has stalled a federal amnesty program and forced former rebels to rethink their participation.
Etugbene Cross is a former rebel commander in the western delta. He told VOA many disenchanted former militants are now anxious to resume attacks on the oil industry.
"Before we started this militant game we did not start it big, we started with local level. So we believe we can start with any local level to disconnect anything and we can do it. We have people, not one person. We are many now," he said.
Resurgent militant activity in the Niger Delta adds to mounting security and political concerns in the troubled African nation.
The Niger Delta rebels say they are fighting for a fairer share of oil revenues for the impoverished residents of the region. In June 2009, the Nigerian government offered a 60-day amnesty to gunmen in the oil-rich region, in a bid to end unrest, which has cost Africa's top oil exporter billions of dollars in lost revenue.
Cross says small bands of rebels will conduct a sustained onslaught against oil pipelines and other facilities in the Niger Delta.
"If the federal government thinks we will go and base in one place and say that is one person's camp, we are not doing anything like that again," he said. "Now anybody can still link us through phone call we are called, five, six people enter boat we go and destroy and come back. Everybody go back to their houses and sit down."
Violence has subsided in the Niger Delta as a result of the amnesty program, allowing some oil companies to repair damaged facilities and boost production to around two million barrels per day.
Nigeria derives more than 90 percent of its foreign exchange earnings from crude oil sales.