LAGOS, Jan 11 (Reuters) - Nigeria's main militant group on Sunday released what it said were pictures of two British hostages seized four months ago and warned it would continue to kidnap European and U.S. oil workers.

The Movement for the Emancipation of the Niger Delta (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. It 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.

Hundreds of foreigners have been seized in the Niger Delta, home to Africa's biggest oil and gas industry, since MEND launched a campaign of violence in early 2006 to push for a fairer share of the profits from crude oil extraction.

Criminal networks have taken advantage of the insecurity, carrying out kidnapping and hijackings for ransom. Most hostages have been released unharmed after a financial settlement. (For full Reuters Africa coverage and to have your say on the top issues, visit: http://africa.reuters.com/ ) (Reporting by Nick Tattersall)

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