By Samuel Elijah
COTONOU, Benin (Reuters) - Armed men hijacked a Cyprus-flagged fuel tanker with 23 crew off the coast of Benin in West Africa on Wednesday, the International Maritime Bureau and Benin's navy said.
The incident is the latest in a string of attacks on ships in the Gulf of Guinea that experts say is threatening an emerging trade hub and growing source of oil, metals and agricultural products to world markets.
"Armed men boarded the product tanker, which was in the midst of a ship-to-ship transfer about 62 nautical miles southwest of the port of Cotonou, and hijacked it," IMB manager Cyrus Mody told Reuters.
He said the ship was being sailed by the armed men to an unknown location, and added he had no details on the nationalities of the crew.
The head of Benin's navy said the ship was the Cyprus-flagged Mattheos 1, and that it was too far off the coast for patrol boats to reach quickly.
"We can't intervene at the moment because of the distance," Navy Chief Maxime Ahoyo told Reuters by telephone. "It would take us at least seven hours to reach the site."
Ahoyo said pirates had also attacked the Nowegian-flagged Northern Bell, which was doing the cargo transfer with the Mattheos 1, but that the crew had locked themselves in the engine room and the pirates eventually left.
The IMB has recorded 19 pirate attacks off of Benin so far this year, from none in 2010 -- a sign that pirates may be moving West of their traditional Nigerian stomping grounds.
"We have reports the Nigerian navy has clamped down on piracy and militancy in their waters," Mody said. "There is a possibility that the Nigerian pirates are going into neighboring Benin waters."
The U.S. envoy to Benin told Reuters last month that Benin was seeking to buy planes to shore up its coastal surveillance as pirate attacks spike.
Mody said that among the attacks, there have been eight hijackings off of Benin this year, but that all of the crews have since been released, usually within 72 hours.
Pirates in the Gulf of Guinea, which stretches from the Guinea to Angola, tend to raid ships for cash and cargo instead of hijacking the crews for huge ransoms like their counterparts off of Somalia.
(Additional reporting by Richard Valdmanis in Dakar; Editing by David Clarke)