A Nigerian militant group behind attacks in the country's oil-rich Niger Delta is urging all such groups to unite and cripple Nigeria's oil industry.

The Movement for the Emancipation of the Niger Delta, or MEND, released a statement Monday that said all "genuine" militant groups should come together and cripple the Nigerian oil industry "once and for all."

Nigerian officials have not commented on the statement, which was e-mailed to journalists.

MEND and other groups in the Niger Delta are demanding the government direct more oil revenue to the region's largely impoverished residents.

Attacks and kidnappings in the Delta have helped to drive down Nigerian oil production by about 20 percent from its peak in early 2006.

Some of the violence was carried out by gangs seeking payment from the government or oil companies.

MEND declared a cease-fire after a new government took office in May promising to address the militants' demands. But the group resumed its attacks after its leader, Henry Okah, was arrested in Angola in September on gun-running charges.

Despite the violence, Nigeria remains sub-Saharan Africa's largest oil producer, pumping more than two million barrels per day.

Some information for this report was provided by AP and Reuters.