Pirates release five Polish, Russian crew taken from ship off Nigeria

ABUJA (Reuters) - Pirates have released five Polish and Russian crew members they kidnapped from a cargo ship off the coast of Nigeria last month, the vessel's management company said.

Piracy is increasing in the west Africa's Gulf of Guinea, an important exporting region for oil, cocoa and metals, and insecurity is driving up shipping costs.

The hostages were taken when the Antigua and Barbuda-flagged MV City of Xiamen container ship was attacked late on April 25 about 100 miles (160 km) off Nigeria's coast.

"Despite difficult conditions while in captivity, they are in good health. They already returned to their own countries and reunited with their families," Sunship Schiffahrtskontor KG, the ship's German operator, said in a statement.

The firm did not say if a ransom was paid but this has been the case in the past.

The International Maritime Bureau had said 14 heavily armed pirates attacked the container ship, breaching its citadel - a strong room designed to protect the crew from attack.

Naval patrols and the presence of armed guards aboard merchant vessels have helped reduce piracy off Somalia on Africa's eastern coast but international navies are not engaged in counter-piracy missions off Nigeria.

(Reporting by Joe Brock)