After a just over a month, 15 seafarers taken hostage off a De Poli Tankers ship have been released.

The seafarers, abducted off the 19,800-dwt Davide B (built 2016) on 11 March, are free, safe and in good condition given the circumstances, the Dutch company said on Wednesday.

De Poli Tankers chief executive Chiara de Poli said they can now return to their families in eastern Europe and the Philippines and begin recovering.

"The past weeks have been an extremely difficult period for everyone, in particular for our 15 seafarers and their families," she said.

"We admire our crew members for their courage during this period and like to thank their families for their patience and resilience during a time of great uncertainty."

The Davide B was sailing in the Gulf of Guinea roughly 210 nautical miles (390 km) south of Cotonou, Benin, when nine armed assailants boarded the ship.

They took 15 of the 21 mostly Romanian, Ukrainian and Filipino crew.

In the aftermath, De Poli said the six remaining on board were tended to by security personnel.

The company was able to make contact with the kidnapped crew six days later, on 17 March.

The waters off West Africa have become increasingly dangerous for shipping in recent months, with several high-profile incidents in the first quarter, including the killing of one seafarer during a kidnapping.

The International Maritime Bureau (IMB) said the region represented 43% of all piracy incidents in the first three months of 2021, with a total of 40 crew kidnapped.

The David B incident was the furthest from shore in the quarter, with IMB director Michael Howlett warning that pirates are willing and able to carry out attacks further from shore.

“It’s critical that seafarers remain cautious and vigilant when travelling in nearby waters and report all incidents to the Regional Authorities and the IMB [Piracy Reporting Centre]," he said.

"Only improved knowledge-sharing channels and increased collaboration between maritime-response authorities will reduce the risk to seafarers in the region."