LAGOS, Nigeria --
A private security official says unidentified gunmen have attacked an oil-industry vessel off the coast of Nigeria and killed its captain.
The official said the captain of the security boat died of gunshot wounds sustained in the attack early Thursday in Nigeria's deepwater offshore oil fields.
The official spoke on condition of anonymity due to company prohibitions on dealings with the media and had no further details.
Attacks on the oil industry have become common in three years of rising violence across the oil-rich southern Niger Delta. Nigeria is Africa's biggest oil producer.