Nigerian officials say a foreign oil worker was killed as the Nigerian military attempted to free seven workers taken hostage earlier Wednesday.

The officials say the other six hostages were freed in the operation, though at least one worker was wounded. They say two of the kidnappers were also killed.

The oil workers were taken hostage when militants raided an Italian oil ship off the coast of southern Nigeria before dawn today.

The ship is operated by a subsidiary of the Italian company Eni. Eni confirmed the rescue operation, saying the deceased worker died as the militants exchanged gunfire with Nigerian marines.

The killed oil worker is believed to be British.

Nigerian militants have kidnapped scores of oil workers, mostly foreigners, in the Niger Delta region this year. The kidnappers usually have released the hostages unharmed after receiving ransom payments.

The militancy is fueled by poverty in villages that have seen few benefits from oil drilling, which generates huge revenue for the government.

The kidnappings and acts of sabotage against oil facilities have forced Nigeria to cut its oil production about 20 percent since February. Nigeria is the biggest oil exporter in Africa.

Some information for this report was provided by AFP, AP and Reuters.