Seafarers were injured when a Swiss bulker was boarded off Conakry in Guinea.
Security companies reported that crew members were attacked during the 30-minute raid on a Marshall Islands-flag vessel 33 km (21 miles) south-west of the port on Thursday.
Ambrey said four criminals boarded the ship with bladed weapons and used force to take money from the safe before fleeing.
The bulker headed into port after the incident.
Swiss owner Suisse-Atlantique said later in a statement the vessel was its 63,000-dwt Nyon (built 2021).
The company revealed the incident took place at 0330 local time at Conakry offshore anchorage.
“All crew members have been accounted for and there are no reports of any injuries,” Suisse-Atlantique added.
The vessel’s general alarm was immediately sounded, and the crew followed all safety protocols and procedures.
“The perpetrators, who unfortunately made away with some of the vessel and crew belongings, quickly fled the vessel upon sounding of the alarm,” the owner added.
The bulker's operational capabilities have not been affected.
Following the incident, the authorities were quickly notified.
“The crew members are now receiving all necessary support following the ordeal and a full investigation by Suisse-Atlantique is underway,” the statement said.
The ultramax had an estimated 8.6-metre freeboard at the time of the attack.
Three merchant vessels were within three miles of the targeted bulker, but none was affected.
Security company Diaplous Group advised all ships in the Gulf of Guinea to take precautionary measures to avoid attacks.
It urged extreme caution and vigilance during operations and while at sea.
Ambrey also said a Liberia-flag bulker heading west in the International Recommended Transit Corridor through the Gulf of Aden called an international coalition warship on Thursday to report it was “being pursued by two skiffs”.
The company observed a minor increase in speed from 10.2 knots to 10.6 knots, but no evasive manoeuvres.
No fishing vessels appeared to be within the vicinity of the bulker, which had an estimated 7.5-metre freeboard. AIS data indicated that armed guards were on board.
According to intelligence received by Ambrey, a warship was responding to the vessel’s distress call.
