Pirates have released seven sailors – six Russians and an Estonian – seized after an attack on a ship operated by French firm Bourbon SA off the coast of Nigeria, Russia's Foreign Ministry said on Thursday.
A ministry statement said the freed crew, kidnapped on 15 October, were "feeling well" and would soon be flown home, but gave no details on how the sailors' release was secured.
After the abduction of the sailors from the vessel, the Liberty Bourbon 249, another nine crew members remained onboard and maintained course toward the Nigerian port of Onne.
The Bourbon is an anchor-handling vessel of the kind used to help supply oil rigs and tow them to a drilling site. The French firm supplies vessels in Nigeria's offshore oil industry.
Pirate attacks are on the rise in Africa's Gulf of Guinea, which is second only to the waters around Somalia for piracy.
Usually, boats are attacked in order to steal their cargo, after which the crew is normally freed. But kidnapping has also become a big criminal enterprise in the waters around the delta, the heart of Africa's biggest energy industry.