LAGOS -- Gunmen kidnapped four American oil workers from a barge off the Nigerian coast yesterday in the 10th attack on Western oil facilities in nine days in Africa's top producer.
Rebels from the Movement for the Emancipation of the Niger Delta (MEND) said they had called for a month of "mayhem" before a new government is inaugurated in Nigeria on May 29, after disputed elections last month.
Militant attacks have already cut output in the world's eighth largest oil exporter by a quarter.
"The Global Cheyenne, a construction barge working in the Okan field, was attacked by unknown armed persons in speed boats," the US oil company Chevron said. "Four expatriate American hostages were taken from the vessel and some government security forces suffered injuries during the attack."
No group claimed responsibility for the latest attack.
But MEND is at the vanguard of an armed insurrection to secure regional control over the delta's oil wealth.
About 100 foreigners have been kidnapped this year in the vast wetlands region, but most were released after their employers paid ransoms. The abduction of the Americans takes the number of foreigners in captivity to 13.