The main militant group in restive southern Nigeria said Tuesday it had bombed three major oil pipelines, disrupting production in two oil fields.
Meanwhile, private security contractors said eight Filipino and three South Korean workers kidnapped by gunmen in the region last week have been released.
The Movement for the Emancipation of the Niger Delta said in a message from an e-mail address frequently used by the group that it had attacked three major pipelines in Bayelsa state. The company that operates the pipelines confirmed the attack.
"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.
Pipelines in the Brass area supply an export terminal that handles 200,000 barrels of crude per day. The Brass terminal is operated by Agip, a subsidiary of Italian oil firm Eni SpA.
Eni's Web site confirmed the pipelines were sabotaged, with production from the Akri and Oshi fields suspended as a precaution. Work to repair the pipelines was under way, it said.
A spokesman for the company declined to comment of the extent of the damage or how much production had been affected. He said he did not know whether a strike by workers in the area Monday was continuing or whether the Brass terminal had been shut down. He declined to give his name, citing company protocol.
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.
Oil slick seen
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 2005 knocked out nearly a quarter of production in Africa's largest oil exporter and 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 says it is fighting for a greater share of the tens of billions of dollars of oil revenues generated in the 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.
Contractors freed
The 11 workers, all employed by Daewoo Engineering and Construction Co., were released to state government officials, said contractors who spoke on condition of anonymity because they were not authorized to talk to the media.
The workers were abducted by an armed group Thursday from Afam power station, about 20 miles northeast of Port Harcourt, Nigeria's southern oil hub. A Nigerian who was seized with them was later released.
There was no immediate word on their health or condition.
Last week, Manila's DZBB radio aired a purported appeal from one of the kidnapped Filipino workers, who said he and the other hostages had not been given adequate food and water and were beaten up by their captors in a forested area. He said he feared for his life and the kidnappers asked him to plead with Philippine officials to work for the hostages' immediate release.
The government later said that Nigerian authorities had assured them of the hostages' safety.
Nearly 100 foreign workers have been seized this year in the region. Some are taken by militant groups demanding a change in government, the release of imprisoned leaders or a greater share of oil revenues; others are simply held for ransom.