Oil companies operating in Nigeria should evacuate staff from the southern Niger Delta following several attacks on oil facilities, a senior oil workers' union official said on Tuesday.
The attacks have pushed Nigeria's crude output near to a 22-year low, sparking worries that militants might resume a full-scale insurgency in the Delta, a region where many complain of poverty despite sitting on much of the country's energy wealth.
Last week, a group known as Niger Delta Avengers attacked a Chevron facility in the Delta after claiming a strike in February against a Shell pipeline, which shut down the 250,000 barrel-a-day Forcados export terminal.
"Best thing for any reasonable company to do is evacuate its workforce," Cogent Ojobor, chairman of the Warri branch of the Nupeng oil labour union, told Reuters.
Chika Onuegbu, chairman of the Trade Union in Rivers state in the Delta, said Chevron had evacuated some staff from the Delta following a similar move by Shell.
"There is high alert around various installation around the Niger Delta due to recent attacks," Onuegbu said. "Those evacuated are where their platforms have been attacked but others are working."
Ikeja Electricity, Nigeria's biggest power firm, said it expected outages after the attack on Chevron hit gas supplies needed to generate electricity.
"Consequently, with this recent attack, the supply line is likely to drop further, leading to extended periods of outages across our network and other parts of the country," the company said in a full-page newspaper statement.
Residents in the impoverished Delta have long demanded a greater share of oil revenues. Crude oil sales account for about 70 percent of national income in Nigeria but there has been little development in the region.
President Muhammadu Buhari has extended a multimillion-dollar amnesty signed with militants in 2009 to end their campaign to blow up pipelines, but upset them by ending generous pipeline protection contracts.
The militancy is a further challenge for a government faced with an insurgency by the Islamist militant Boko Haram group in the northeast and violent clashes between armed nomadic herdsmen and locals over land use in various parts of the country.