Pirates kidnap two in attack off Nigeria: watchdog Armed pirates opened fire on a cargo ship in an attack off the Nigerian coast, kidnapping the captain and chief engineer and robbing the crew before escaping, according to a maritime watchdog. Tuesday's attack also left one crew member missing and another injured, the International Maritime Bureau (IMB) said, and was the latest in a series of incidents indicating heightened piracy in the Gulf of Guinea. The assault at about 1500 GMT Tuesday targeted a Dutch-owned, Curacao-flagged refrigerated cargo ship that was anchored near the coast, said Noel Choong, head of the IMB's Kuala Lumpur-based piracy reporting centre. A group of about eight pirates armed with guns carried out the attack on the ship, which had a crew of 14, he said, adding that Nigerian authorities had been alerted. Choong said he had received no word yet on the fate of those reported missing or whether any ransom was being demanded. "The attacks off the Nigerian coast are very violent and they are increasing," Choong said. So far we have seen seven attacks off Nigeria this year and one off of Benin. So that makes eight since the beginning of the year and we believe many more attacks may have gone unreported. Two weeks ago, pirates fired on a cargo vessel off Nigeria, killing the ship's captain, according to the IMB. Choong said that vessel's chief engineer died from a fall during the attack, correcting earlier reports that he also had been shot dead. That ship was Panamanian-flagged but its owners were Taiwanese, he said. The IMB has said other recent attacks in the area included a tanker that was hijacked south of Nigeria earlier in February. Nigerian vessels intercepted that ship and rescued its crew. The IMB, which is funded by shipowners, warned in September that the seas off Benin, Nigeria's neighbour, were emerging as a new piracy "hotspot" due to the weak enforcement capabilities of governments in the region.