All crew on a Maersk containership are safe after the vessel was boarded by pirates off Nigeria.

The incident took place on 5,466-teu Maersk Tema (built 2015), which is operated by the Danish company and owned by Germany's Schulte Group, 170 nautical miles (315km) south-west of Bayelsa on Friday morning.

Piracy reporting organisation Maritime Domain Awareness for Trade-Gulf of Guinea (MDAT-GoG) issued a warning that a vessel had been attacked and boarded by pirates.

Manager Bernhard Schulte Shipmanagement (BSM) confirmed that at approximately 0900 local time the ship was involved in a security incident off the coast of Guinea.

"All 21 crew members are safe and well aboard," it said.

"The crew observed a suspicious approach from two skiffs and activated their emergency response procedures. Both the Nigerian and Portuguese navies attended the vessel's request for assistance."

The company said Nigerian marines conducted a full security sweep of the vessel and found no threats on board.

"We would like to thank the crew for their professionalism, as well as the Portuguese navy, Nigerian navy and all other parties who provided their assistance," it added.

"The vessel is now safely underway to anchorage with a security escort. All appropriate maritime authorities have been notified."

Security consultancy Ambrey said: "It has been verified that the pirates did board the containership and escaped before interdiction by authorities.

"All crew members have been accounted for. She is now under the protection of a security escort vessel. It is strongly advised that vessels maintain a heightened security posture in the region."

The ship was underway at 19.4 knots minutes before the attack.

After the incident, it slowed, changed course and began to drift.

Consultancy Dryad Global said two pirates were believed to have boarded the vessel.

Crew members were said to have reached the citadel.

According to AIS, it was destined for Lagos. The last port of call was Pointe-Noire.

Its AIS remained switched on Friday and showed the vessel stopped in mid-ocean.

BSM had told TradeWinds earlier: “We can confirm that the BSM-managed vessel, Maersk Tema, was approached by two skiffs in the Gulf of Guinea.

"The crew followed emergency protocol."

It added: “BSM has reported this incident to the Guinea Anti-Piracy Reporting Centre, and is working with all relevant maritime authorities in the region.”

Warning issued

Security broker Asket also reported the incident and warned: "Mariners are advised to exercise extreme caution in this area."

The last reported attack in the dangerous Gulf of Guinea region came at the end of January when a pirate gang abducted a passenger from a ferry off Cameroon.

The incident took place 9km off Limbe.

The vessel was said to be underway off the port when it was approached and boarded by at least six people in a single speed boat.

The kidnapped passenger was later seen being taken towards the Bakassi peninsula.

The ferry raid brought to an end a quieter period off West Africa, following a hiatus in a series of kidnappings and attempted boardings over recent months.

Before that, a reported attack involved a group of 15 pirates pursuing and firing on an MSC-operated multipurpose ship off Nigeria on 21 January.

The 24,000-dwt MSC Grace (built 1991) was en route from Lagos to Port Harcourt at 12 knots when it was attacked 18 nautical miles south of Bayelsa.