Dutch shipmanager Seatrade is working round the clock to establish contact with two crew members abducted from one of its reefers off Nigeria on Tuesday.
The company confirmed the kidnapping by pirates from the 400,884-cbf Water Phoenix (built 2002) 61 km from Lagos, but did not provide further details.
Security consultancy Ambrey said the Russian pair were the master and a mate.
"The remaining 16 seafarers are safe and unhurt. Water Phoenix meanwhile is proceeding to her berth in Lagos escorted by navy," Seatrade said.
"Seatrade would like to stress its main priority is to establish contact with the missing seafarers and secure their earliest and secure return."
24-hour operations
The manager continued: "The company’s emergency response team is working around the clock and is liaising with the local and international authorities."
Seatrade said it was also in close contact with the families of the seafarers to support them in these difficult times.
The reefer outfit is not providing any further information in order not to jeopardise the safety of its seafarers.
The Liberian-flagged vessel was en route from Ijmuiden in the Netherlands to Lagos.
The vessel had a low freeboard, estimated by Ambrey at 2.3 metres.
The ship was boarded despite evasive manoeuvres and an increase of speed to 14.9 knots. Within five minutes it was adrift.
This is the second time the vessel has faced an attack in the region. The first was deterred by armed guards, but Ambrey said it appeared unlikely any armed personnel were on board at this time.
Piracy reporting bodies had warned last week of a renewed threat of an attack by a pirate group based in Nigeria's Rivers State.