Six sailors were kidnapped when pirates attacked a ship with a Russian crew off the coast of Benin in West Africa, Russia’s Maritime and River Transport agency confirmed.

A group of seven to nine attackers, armed with firearms and blades boarded the Panama-flagged MSC Mandy on Tuesday night, according to the maritime authority and the Russian embassy in Benin. The pirates pillaged the ship for two hours before leaving and taking six of the sailors on board with them.

Incident Alert - Gulf of Guinea - 02/01/2019 MSC Mandy Attacked and Crew Hijacked. See here for full details and an early assessment of the threat in the region: https://t.co/qPyGuv6dIL — Neptune P2P Group (@neptune_p2p) January 3, 2019

There were 23 Russians and one Ukrainian among the crew members, according to the Russian maritimy authority. The embassy, citing the Benin Navy, says there were 26 people: 20 Russians, four Ukrainians and two Georgians.

The captain, his chief mate and third mate, a boatswain, a fitter-welder and a cook, all Russian citizens, have been kidnapped. The other crew members remain aboard unharmed.

The attack reportedly took place around midnight some 55 nautical miles off Cotonou, a large port city on the south coast of Benin.

Following the attack, the MSC Mandy headed to the port of Lagos and is expected to sail further to Cotonou, under a substitute chief mate. Substitute crew members are expected to join the rest of the sailors in Cotonou.

The vessel is currently moored at Gulf of Guinea, according to Marinetraffic.

The area off the coast of Benin and neighboring Nigeria is considered high-risk waters. There were five reported pirate attack near Cotonou and more than 20 near Nigeria’s Lagos last year.

Russian diplomats in Nigeria and Benin are working to release the captured sailors, RIA Novosti reported. No demands have been made so far.