Gunmen in Nigeria have kidnapped Friday at least eight more foreign oil workers in the country's Niger Delta region. Kari Barber reports for VOA from Abuja.

Nigerian police say the workers were taken from an off-shore facility in southern Bayelsa State by men who arrived by boat. Diplomats in Nigerian say the kidnapped workers include three Americans, at least two British nationals and one South African.

More than 100 foreign oil workers have been kidnapped so far this year in the Niger Delta, at least 40 of them in the month of May alone. On Thursday, a Polish oil worker was abducted in the southern city of Warri.

Militant groups in the delta say they are fighting for a more equal distribution of the region's oil wealth. The kidnaped workers are usually released unharmed, after a ransom is paid.

Niger Delta community activist Charles Johnson lives in one of the areas where many militants operate. He says although he does not support kidnapping oil workers, he understands the militants' frustrations at the persistence of poverty in a land rich in oil wealth.

"We hail them in certain actions they take," he said. "We have to fight for our rights. The only place we do not support them is when it comes to hostage taking and all of those things, we do not really go for that. It creates more tension and spoils the relationship between Nigeria and other countries. So it is not really the best form of fighting for your rights."

In recent weeks, the militant groups have begun kidnaping foreigners not working in the oil sector.

Aid workers who try to negotiate with the militants say they have been asking for as much as one million dollars per group of hostages.

In an e-mail sent to reporters, the main militant group, known by its acronym MEND, said it had nothing to do with Friday's kidnapping.

Militants vowed a month of mayhem in May to coincide with the final days of the presidency of Olusegun Obasanjo. He will hand over power to his successor, Musa Yar'Adua, on Tuesday.