The piracy threat in the Gulf of Guinea is rising again after a quiet period, shipowners have been warned.

British and French piracy reporting body Maritime Domain Awareness for Trade — Gulf of Guinea advised ships to be extra-vigilant in Zone E, which covers Togo, Benin and Nigeria.

Security company Africa Risk Compliance (ARC) said: "There has not been a piracy attack for over a month in West Africa and no crew are currently held by pirates, so it is likely that pirates may attempt an attack in the next fortnight.