A Chinese multipurpose cargoship (MPP) has become the latest victim of a pirate group off Nigeria, marking the third attack in the area on the same day.
But all crew were later reported as safe following the incident.
Maritime Domain Awareness for Trade-Gulf of Guinea (MDAT-GoG) reported a "possible boarding" by gunmen 81 nautical miles (150 km) off Lagos, Nigeria, at 1827 GMT on Thursday.
The targeted ship was the 28,300-dwt Huanghai Glory (built 2012), operated by Tianjin Xinhai International Ship Management of China.
MDAT-GoG said later on Friday that it had confirmed that all the crew members were safe and the vessel was once again underway.
The Chinese manager had earlier confirmed to TradeWinds it had not been able to contact the ship following the attack, but it added it could not give further details on the number of crew on board.
Maritime security company Dryad Global said Huanghai Glory had sent an alert during the attack.
The number of pirates involved is not known.
Navy investigating
Dryad added: "Currently, the vessel is drifting, with 23 crew members on board believed to be Chinese nationals. Nigerian navy has been informed and has dispatched a vessel to investigate."
Security consultancy Ambrey said the attack took place inside the Nigerian exclusive economic zone, while the status of the ship and the crew was unknown.
The last AIS update showed the MPP anchored in Lagos on 27 February.
Same group responsible?
The news means three separate attacks were attempted on Thursday, highlighting the ever-present threat to vessels in the region.
The first saw a crewman reported missing six hours earlier from the 51,000-dwt Minerva Marine MR tanker Minerva Virgo (built 2006), 83 km off Cotonou, Benin.
This in turn was five hours after an approach to a Marshall Islands-flagged MR tanker, underway at 11 knots off Lome, Togo.
Dryad said it is "highly likely" that the perpetrators of all three incidents are the same grouping and are highly likely to have originated from within Nigeria.
"Since 2019 there has been an increase in maritime security incidents involving vessel boarding and kidnappings within the waters off Togo and Benin but also a slight increase in incidents beyond the generally accepted heart of Nigerian piracy within the Niger Delta area," the consultancy added.
"This is, in part, assessed to be due to the increased risks facing perpetrators within the Nigerian EEZ as a result of enhanced security coordination and the increasingly prevalent use of security escort vessels."
This, combined with an effective lack of coordinated security measures beyond the Nigerian EEZ, has led to perpetrators to travel further in search of high yield targets, Dryad added.
"In this particular incident, it is highly likely that the perpetrators sought to target a vessel whilst in transit to their original location," the company said.
