Nigeria ? Eleven armed men attacked a southern Nigeria oil facility owned by a subsidiary of Royal Dutch Shell PLC Wednesday, leaving two attackers dead, police officials said.

The assailants were repelled by naval forces as they attempted to shut down the Oporoma station, said Hafiz Ringim, police commissioner for Bayelsa state. He said two of the attackers were killed in the fighting and one was captured.

No damage was reported to the flowstation, which connects oil pipelines.

Shell spokesman Bisi Ojediran confirmed that Oporoma had been attacked but said he had no further details.

Police said the captured man told them that the group mounted the assault to recover the balance of a ransom that was never fully paid after a hostage-taking last month.

The same flowstation was attacked last month, when staff were held for two days and the facility was looted. It was not immediately clear whether the captured man was referring to this incident.

More than 60 foreigners have been kidnapped in Africa’s largest oil producer since the beginning of the year, and several times that number of Nigerians.