PORT HARCOURT (Nigeria), Sept 22: More than 100 armed militants stormed a US-operated oil production platform in Nigeria and forced it to close on Thursday in response to the arrest of an ethnic militia leader on treason charges.

Armed with assault rifles, the fighters invaded the Idama platform operated by Chevron in the southern Niger Delta, escalating a simmering political crisis in the world’s eighth largest oil exporter.

“Eight boats, each carrying 15 armed people occupied the Idama flow station. Six government security forces had their weapons taken from them,” a source close to Chevron said.

“Apparently the militants are now heading for more stations. The situation can only get worse.”

Only about 8,000 barrels per day were affected at Idama, a company source said, but industry officials said the impact of unrest could rise dramatically if security worsened.

Chevron officials were not available for comment.

Militants loyal to Mujahid Dokubo-Asari burned tyres in the streets of the delta’s largest city, Port Harcourt, and blocked a major road artery. Police shot in the air to disperse them.

Asari’s Niger Delta People’s Volunteer Force (NDPVF) threatened on Tuesday to cause mayhem and close down oil facilities in the delta, which pumps all of Nigeria’s 2.4 million barrels per day, unless their leader was released.

Royal Dutch Shell evacuated non-essential staff from one of its platforms, but a senior industry source said the 70,000 barrels-a-day output from that facility would be maintained by a skeleton staff.

Oil prices are near record highs due to hurricane damage in southern United States, and any disruption to exports from Nigeria, its fifth largest supplier, would make the situation more precarious.

Asari campaigns for self-determination of his Ijaw tribe, the largest in the delta, and argues that the colonial treaties that created the union with Nigeria were fraudulent.

The government has called him an oil thief and gangster.

The NDPVF had demanded his release by 1300 GMT on Wednesday.

An Abuja high court on Thursday granted a request by the justice minister to detain him for two weeks to prepare charges of treason, which carries a maximum death penalty, and unlawful assembly.—Reuters