Pirates stormed a cargo ship off Nigeria's oil-producing southern coast, kidnapping five foreign sailors and stealing cash, a watchdog and a security source said Monday.
The International Maritime Bureau (IMB) said the April 25 incident was carried out by "14 heavily armed pirates" who boarded the vessel 45 nautical miles off the Nigerian town of Brass.
They forced their way into the ship's saferoom, making off with crew and cash, the IMB said in a statement.
A security source, who asked that his name be withheld, said those taken included three Sri Lankans, a Russian and a sailor from Myanmar.
The Gulf of Guinea, which includes the waters off Benin, Nigeria and Togo, is as emerging piracy hub, with the number of attacks in the region having risen for three consecutive years.
Often the foreigners taken are released following a ransom payment.
The pirates have also stolen crude oil from ships servicing Nigeria's oil industry, which is the eighth largest in the world.