"The BBC Caribbean ship came under a pirate attack in the territorial waters of Nigeria," the Russian embassy tweeted. "Seven Russian citizens and one Ukrainian citizen have been abducted from the ship. The Russian embassy has asked the Nigerian authorities to assist in establishing the whereabouts of the abductees," TASS said.

The embassy's spokesman Artyom Romanov said that "all necessary measures are being taken to find out where the kidnapped Russian sailors are at the moment."

Read alsoPirates capture two Ukrainians, two Lithuanians off coast of Nigeria - MediaMaritime Herald, a maritime and shipping news outlet, said on Tuesday the general cargo ship BBC Caribbean was attacked by pirates in the Gulf of Guinea 45 nautical miles south-west off Brass, Nigeria. The accident happened near Pennington Oil Terminal at Nigerian Delta, when the cargo ship was approached by a motor skiff with armed men on board, who opened fire. The guards on board of the general cargo ship BBC Caribbean returned fire.

On November 27, 2016, three Russian sailors were taken hostage when the Saronic Breeze ship was attacked in the territorial waters of Benin. On December 20, all were freed.

On February 23, 2016, the Bourbon Liberty 251 ship belonging to a French company was seized by pirates in the Gulf of Guinea. The attackers eventually fled taking two hostages, one of them Russia's Ivan Rudny. He was freed in March 2016 to return to his family in Murmansk.