Pirates in the Gulf of Guinea have hijacked an Italian fuel tanker with 23 crew members on board.

The Italian news agency ANSA reports that three pirates seized control of the RBD Anema e Core on Sunday.

It says the ship was carrying a cargo of diesel fuel and that the ship's crew consists of 20 Filipinos, two Italians, and a Romanian captain.

Italy's foreign ministry says its crisis unit is following the situation, and is in contact with the ship's owner, based in the Italian city of Naples.

Pirates in the Gulf of Guinea off West Africa's southern coast have become increasingly active in recent months.

Two Greek-operated tankers were recently seized in the area, one on June 16 and the other on July 16.

Last month, the International Maritime Bureau issued a piracy warning for ships traveling near the country of Benin.