In an e-mail to journalists, the Movement for the Emancipation of the Niger Delta said it carried out Sunday night’s attack on the oil rig located off the coast of Akwa Ibom state, the home of Exxon Mobil’s Nigerian subsidiary.

The militant group said fighters boarded the rig and “detonated explosives they had earlier rigged to this facility, causing considerable damage.” The group said it kidnapped the local workers to “prevent the Nigerian government from attributing the damage to this facility to an industrial accident.” It also warned the group would launch new attacks throughout the winding creeks and mangroves of the Niger Delta, a region about the size of Portugal where Nigeria pumps out the crude oil that sustains its economy.

“In the coming weeks, the Movement for the Emancipation of the Niger Delta (MEND) will launch a major operation that will simultaneously affect oil facilities across the Niger Delta,” the statement said.

A spokesman for Exxon Mobil’s Nigerian subsidiary did not immediately respond to a request for comment Tuesday.

Upset by the region’s endemic poverty and the pollution caused by 50 years of oil production, militants in the Niger Delta have attacked oil pipelines and kidnapped workers since beginning an low-level insurgency in 2006.

MEND, a loose confederation of fighters, claimed responsibility for much of the violence and sent regular communiques to journalists to become the region’s de facto militant group.

The group’s statement accused Nigeria’s government of not committing to dialogue to resolve the region’s problems.

They accused the administration of President Goodluck Jonathan of “only being successful in bribing a few miscreants.

Many former commanders and fighters laid down their weapons last year as part of a government-sponsored amnesty deal, which offered cash payouts and the promise of job training. However, a faction of MEND continued fighting and claimed responsibility for an Oct. 1 car bombing that struck Nigeria’s capital, Abuja, during an independence anniversary celebration, killing at least 12 and wounding dozens more.

Authorities in South Africa arrested alleged gunrunner Henry Okah, a suspected MEND leader, after the car bombing.

He now faces terrorism charges over the October bombing.

MEND launched a series of similar attacks after Okah was arrested in 2006, only pausing their campaign until after the Nigerian government released him and dropped the gunrunning and treason charges against him.

It is unclear whether Okah’s current detention roused MEND to action. Last week, MEND claimed responsibility for an attack on an oil rig operating off the coast of Akwa Ibom state for London-based Afren PLC. Militants kidnapped seven workers in that attack; two from the United States, one from Canada, two from France and two from Indonesia.

In the e-mail Tuesday, MEND also claimed the Nigerian army carried out an attack Monday against one of its camps in the Niger Delta. The group said it rockets fired by the military “came very close” to hostages.

“The Nigerian government should be mindful of the fact that these activities are endangering the lives of these hostages who otherwise, would come to no harm in our custody,” the statement read. “No amount of military activities will secure the release of these hostages. They will be released at our time.”