The main militant group in restive southern Nigeria said Tuesday that it has bombed three major oil pipelines.

The Movement for the Emancipation of the Niger Delta said in an e-mail address frequently used by the group that it had attacked three major pipelines in Bayelsa state.

"Fighters of the Movement for the Emancipation of the Niger Delta attacked and destroyed three major pipelines ... We will continue indefinitely with attacks on all pipelines, platforms and support vessels," the e-mail stated.

The claim was not immediately verifiable by the Nigerian authorities or by Eni SpA, whose subsidiary Agip operates the Brass export terminal. Previous announcements of attacks have proved true. The terminal exports 200,000 barrels of crude per day.

Chief Joshua Benemesia, head of a government-backed anti-piracy force, said he had confirmed the attack with members of the Bayelsa State volunteers who were stationed in the two areas attacked, Brass and Akassa. He had no information on the capacity of the pipelines attacked.

A private security contractor, who is not authorized to speak to the media, confirmed that a large oil slick was spreading down the river from the Brass area.

The Niger Delta, a wetland the size of Connecticut, is veined with thousands of miles of pipelines snaking their way through the mangrove swamps. Much of the Delta is impassable except by boat. Attacks on isolated oil pumping stations or staff are frequent.

A previous bombing by MEND in December of 2005 knocked out nearly a quarter of production in Africa's largest oil exporter which has still not been restored. The militant group also recently claimed responsibility for the kidnapping of six foreign oil workers last week from a Chevron-operated facility and on Tuesday sent photos of them from the same e-mail address used to claim responsibility for the bombings.

MEND say they are fighting for a greater share of the tens of billions of dollars of oil revenues generated by their impoverished region, and the freedom of two leaders on trial for treason and corruption charges.

Despite its oil wealth, Nigeria remains deeply impoverished and riddled by massive government corruption. Most of its inhabitants have no access to electricity, clean water or health care.

Militant attacks in the west African country, which produces the highly desirable light sweet crude oil that is easy to refine, often rattle oil markets already jittery over instability in the Middle East.