The Movement for the Emancipation of the Niger Delta blamed the resumption of the attacks on the suspended peace talks due to President Umaru Yar'Adua's absence.
The rebel group responsible for most of the attacks in Nigeria's oil producing region says it destroyed a major crude pipeline in "a warning" strike early Saturday. The Movement for the Emancipation of the Niger Delta (MEND) says 35 of its fighters, armed with assault rifles and heavy machine guns raided an oil facility jointly operated by Royal Dutch Shell and Chevron in Rivers state.
The group met with President Umaru Yar'Adua last month at the start of peace talks. But the process has been stalled by Mr. Yar'Adua's absence from Nigeria in the past few weeks. The Nigerian leader is receiving medical treatment in Saudi Arabia for a heart condition.
A statement by MEND said "a situation where the future of the Niger Delta is tied to the health and well-being of one man is unacceptable." The group says it may review an indefinite cease-fire it declared after 30 days.
The Catholic bishop of the Niger Delta town of Bomadi, Hyacinth Egbegbo, is urging the militants to stay calm saying only a negotiated peace can bring lasting stability to the troubled oil-rich region.
"Let us go for peace, not for any more struggles," said the bishop. "Armed struggle is not going to be in favor of any Nigerian. So let us sit down at the table and see that we resolve these problems amicably. I appeal to the boys to take their guns away from the dialogue that is being initiated by the government. Because dialogue with guns is not dialogue. So let us put the guns aside and speak words of wisdom to each other so that we can come to a more amicable solution to the problem."
The militant group, which says it is fighting for a fairer share of the region's oil wealth, crippled daily oil production with series of attacks on oil facilities and personnel since early 2006.
But MEND has been severely weakened since dozens of its field commanders and thousands of gunmen accepted President Yar'Adua's amnesty offer and disarmed.
The Niger Delta remains a stronghold for gangs and militant groups with strong opposition toward foreign oil companies and the government.
Security analysts say the oil industry remains vulnerable to opportunistic attacks, crude oil thefts and kidnappings. Nigeria plans to offer inhabitants of the Niger Delta an extra 10 percent in oil and gas revenues in a bid to end the rebellion.