Lagos — Movement for Emancipation of the Niger Delta (MEND) yesterday released pictures of two British hostages it has been holding for four months, and said it would continue to kidnap European and U.S. oil workers until its demands are met.

MEND said in an e-mailed statement, that the two Britons, whom it named as Robin Barry Hughes and Matthew John Maguire, were alive and well and attached what it said were recent pictures.

"Our policy on kidnapping high-value oil workers from Western Europe and North America remains unchanged and will continue to form an integral part of our pressure strategy in the emancipation struggle in 2009," MEND said.

It warned that it would hold the men until Henry Okah, leader of MEND who is on trial for gun-running and treason, was released.

"We intend to hold on to (the Britons) for as long as a very sick and dying Henry Okah is held hostage by the Nigerian state. Since their fate is now tied to his, God forbid that Henry Okah dies in detention," the e-mail added.The photos showed the two hostages wearing shorts and flip-flops in what appeared to be a makeshift settlement in a clearing in thick forest.

Both looked tired but had no visible signs of serious illness or injury.

They were first kidnapped on September 9, 2008, with two South Africans, a Ukrainian and more than 20 Nigerians when their oil supply vessel was hijacked.MEND said a few weeks later, it had "rescued" all of them from their original captors.

It has since released the South Africans, the Ukrainian and the Nigerians, but said it was holding on to the Britons as "leverage."

Hundreds of foreigners have been seized in the Niger Delta, since MEND launched a campaign of violence in early 2006, to push for a fairer share of profits from crude oil extraction.

Criminal networks have taken advantage of insecurity in the region to carry out kidnappings and hijackings for ransom.Most hostages have been released unharmed and relatively quickly after a financial settlement.MEND had in the past, used the British hostages to warn the British government against offering any training or equipment to the Nigerian armed forces.Britain, like other foreign countries, has a long history of joint training exercises with the Nigerian military.The British government said last July it would send experts to help train Nigerian soldiers in the oil-rich region.MEND's campaign of violence, which has included blowing up oil pipelines and attacking installations on and off-shore, has cut Nigeria's oil output by around a fifth, in recent years.