Eight pirates armed with machine guns fired at a Curacao-flagged vessel anchored at southeast Nigeria's port Harcourt before boarding the ship Tuesday night, Micheal Howlet told Xinhua, adding that the chief engineer and the ship master were taken hostage.
The vessel has 14 crew members, he added, noting that one crew member was injured and another was reported missing.
The attack came only two weeks after armed pirates attacked a Panama-registered Chinese cargo ship near the port of Lagos in the early morning of Feb. 14.
The pirates stole goods and escaped when a nearby foreign naval ship came to the crew's rescue.
Piracy and armed robbery in the gulf have been increasing in recent years, drawing the attention of the international community.