Nigerian militants today warned oil firms in the Niger Delta to withdraw their workers in the next 24 hours or face a "hurricane" of retaliation after a major gun battle with security forces.
The Movement for the Emancipation of the Niger Delta (MEND), responsible for attacks that have cut more than a fifth of the Opec member's oil output, threatened to target oil workers after it said seven people were killed in fighting between security forces and militants in Tombia, in Rivers state.
"Oil companies are warned to move out their workers within the next 24 hours because a hurricane is about to sweep through oil installations in the entire Niger Delta region," MEND, the country's most prominent militant group, said in an emailed statement.
Royal Dutch Shell, ExxonMobil, Total, Eni and Chevron are among the numerous oil companies that operate in the restive Niger Delta, the main source of Nigeria's two million barrels per day output.
A Shell spokesman in Nigeria said the company did not comment on security matters.
MEND said security forces had used helicopters, jet fighters and over 20 gunboats in today's fighting. "This may be the beginning of a full scale oil war," the group said.
A security source said soldiers from the army, navy and air force were involved in the clashes.
Lieutenant Colonel Sagir Musa, spokesman for the military task force in Rivers state, played down the fighting and said the clashes had begun after militants attacked a military patrol boat.
He said there were no casualties, adding: "The situation is under control. There is no cause for alarm."
Security in the Niger Delta worsened dramatically in early 2006 when militants, who say they are fighting for more local control of the impoverished region's oil wealth, started blowing up oil pipelines and kidnapping foreign workers.
Gunmen in the Delta hijacked an oil supply vessel on Tuesday with two Britons, two South Africans and a Ukrainian on board.
President Umaru Yar'Adua took office 16 months ago promising to bring stability to the Delta, but has seen little success and has looked overseas for help.