THE HAGUE (AFP) - Niger Delta gunmen have released three Dutch nationals who were abducted earlier this week, a Nigerian activist who had accompanied the trio but was earlier released said on Saturday.

Amsterdam-based environmental activist Sunny Ofehe and the three Dutch nationals, two men and a woman, were seized on Sunday after armed men in a dinghy stormed their boat.

The group, which included another Netherlands-based Nigerian, were blindfolded and eventually taken to an unknown location where the two Nigerians were abandoned.

"I just want to inform everyone that they are free, and that they are safe and in good health," Mr Ofehe told Dutch broadcaster NOS TV.

Scores of foreigners have been abducted in the southern Niger Delta region, home to Africa's largest oil industry, with many released on payment of a ransom.

Employees of foreign oil companies are required to have an armed escort when travelling in the Delta, but international journalists, aid workers and others typically avoid taking a security detail.

Dutch printing company Gerrits & Leffers had confirmed that two of its employees were among those abducted and that the pair were in Nigeria to help Niger Delta peace activists publish a magazine.

The third Dutch national was a documentary filmmaker, NOS TV reported, and the group was en route to visit a hospital financed by oil company Chevron when the kidnapping took place.