Pirates have released five Russian and Polish nationals kidnapped from a cargo ship last month off the coast of Nigeria.
The ship's German operator confirmed Tuesday all five crew members were released on May 11, that they are in good health and have returned to their home countries.
The company did not say if a ransom was paid, but ship owners often hand over large sums to free abducted sailors.
The crew members were kidnapped April 25, when 14 heavily armed pirates forced their way into the cargo ship's citadel, a strong room designed to protect the crew from attack.
Piracy is increasing in West Africa's Gulf of Guinea, with gunmen frequently targeting oil ships to steal crude and seize foreign hostages for ransom payments.
The International Maritime Bureau has recorded 19 piracy incidents off Nigeria this year.