Pirates have kidnapped nine seafarers from a Greek tanker after boarding the vessel off Benin in the early hours of Thursday, according to security consultancy Dryad Global.

The nationalities of the abducted crew were not known, but Oceangold Tankers' 74,000-dwt Alpine Penelope (built 2008) reportedly had 24 seafarers on board from Georgia, the Philippines and Ukraine.

Piracy reporting body MDAT-GoG had earlier said a vessel had been attacked 74 nautical miles off Cotonou an hour after midnight.