U.S. sailors and Nigerian special forces on a training exercise off the Nigerian coast in 2010. The U.S. Navy has offered training to the Nigerian navy amid concerns of increasingly violent pirate attacks along the West African coast. Jon Gambrell/AP Photo

Pirates attacked an oil-supply vessel off Nigeria’s coast and kidnapped the captain and chief engineer, both U.S. citizens, an American defense official and security sources said Thursday. The incident is the latest in a surge of pirate attacks in the Gulf of Guinea.



The U.S.-flagged C-Retriever, a 222-foot vessel owned by the U.S. marine transport group Edison Chouest Offshore, was attacked early Wednesday, according to the U.K.-based security firm AKE and two security sources. The company was not immediately available for comment.

A U.S. defense official said the State Department and FBI were leading the American response to the incident. A second defense official said the Marine Corps has a small training unit in the region, but it was not clear if the unit would get involved.

Navy officials have grown increasingly concerned about piracy and armed robbery in the Gulf of Guinea and are working with local authorities to strengthen their ability to patrol the region.

Navy Secretary Ray Mabus had called the region a potential "hot spot" after a visit to four countries surrounding the gulf in August. He told Defense News in September that the Navy was working closely with Gabon, Senegal, Sao Tome and Principe, and Ghana to help fight an increase in illegal trafficking of drugs, people and arms.

Pirate attacks off the Nigerian coast have jumped by a third this year as ships passing through the gulf, a major commodities route, have been increasingly targeted by gangs hoping to raid cargo and kidnap crews.

"The piracy threat is spreading even further through the waters of West Africa, and the attacks have been mounting, even as global rates of reported piracy are at their lowest since 2006," said Michael Frodl of the U.S.-based consultancy C-Level Maritime Risks.

In the dangerous waters off Somalia and the Horn of Africa on the continent's east coast, ships now speed through with armed guards on board. But in West Africa, many vessels have to anchor to do business off the coast, with little protection.

This makes them a target for criminals and raises insurance costs. Kidnapped sailors and oil workers taken in Nigerian waters are usually released after a ransom is paid.

In a separate incident, three Nigerian soldiers were killed on Tuesday when armed robbers attacked a vessel carrying construction workers in the creeks of oil-producing Rivers state, the army said Thursday.

Reuters