Abuja  - Niger Delta militants abducted five Russians on board a Swedish vessel, the Herkules, offshore Bonny River Friday, security officials said.

The vessel was sailing to Akpo oil field when the militants seized it at 19 nautical miles offshore. it was on charter to Saipem, a subsidiary of ENI group of Italy.

Local reports said that 11 Russians and one Ukrainian were on board the vessel when the militants attacked it from speedboats.

The militants took control of the vessel and steered it toward Sombereiro River, 15 nautical miles west of Bonny River, the reports said.

The militants later freed seven of those on board and took five Russians hostage.

A spokesman for special troops deployed in the Niger Delta to provide security for oil facilities and workers, army Lieutenant Colonel Sagir Musa, confirmed the attack.

Musa also said gunmen kidnapped a Filipino and a Nigerian Friday at the Borokiri area of Port Harcourt. No group had claimed responsibility or demanded any ransom for Friday's kidnappings.

Militants have been taking hostages and atttacking oil production facilities to press their demands for a greater say in the exploitation of oil and gas resources from the Nigerian government.

Because they often release the victims after collecting ransom money, the government has dubbed them criminals who also steal crude oil in exchange for arms, ammunition and money.

One of the main militant groups in the Niger Delta, the Movement for the Emancipation of the Niger Delta, condemns such criminal acts, accusing those involved of not fighting the Niger Delta cause. (dpa)