The shipping insurance industry has added Benin to a list of areas deemed “high risk” because of increasing piracy.

Pirates recently hijacked several vessels in the Gulf of Guinea off Benin, including at least two oil tankers.

The so-called Joint War Committee, which represents Lloyd's of London underwriters and other insurers, has given the waters off Benin a high risk designation for the first time. It also expanded the high risk zone for waters off Nigeria.

The move allows insurers to charge an extra premium for ships entering those areas.

The International Maritime Bureau issued a piracy warning for Benin back in June. The bureau says the waters off Somalia remain the world's most piracy-prone area but warns that attacks are increasing off the Benin coastal city of Contonou.

It also says the Benin pirates are violent and often injure crew members.