Lagos: A Nigerian official says pirates armed with Kalashnikov rifles clashed with Nigerian navy forces in a failed bid to take over an offshore oil platform, then kidnapped three French employees of a marine services company while retreating.

Navy Commodore David Nabaida said Wednesday a Thai employee also may have been taken hostage by the pirates during the attack.

The French-flagged vessel Bourbon Alexandre was working in an offshore oil field operated by Addax Petroleum, a subsidiary of Chinese state-owned oil producer Sinopec Group.

The Movement for the Emanicipation of the Niger Delta, the main militant group fighting the government in the region, issued a statement late Wednesday night to The Associated Press saying its members were "in negotiations with the abductors" to have them released into their care.