Dutch operator ForestWave has said 12 crew have been seized from a general cargoship by Nigerian pirates.
It had earlier said that gunmen boarded the 10,600-dwt FWN Rapide (built 2005) on Saturday morning as it prepared to enter Port Harcourt, Nigeria.
Two seafarers have remained on board and are safe and unhurt. They have moved FWN Rapide to a safe position.
"ForestWave would like to stress its main priority is to establish contact with the missing seafarers and secure their earliest and secure return," it said.
"The company’s emergency response team is working around the clock and is liaising with the local and international authorities.
"ForestWave together with its local organisations are in close contact with the families of the valued seafarers to support them in these difficult times."
It praised the two crew for their "courageous and professional handling of the situation and moving FWN Rapide to a safe location after the attack."
It will not provide any further information in order not to jeopardise the safety of those involved.
The vessel was en route from Takoradi, Ghana, to Port Harcourt, Nigeria.
Incidents rising
There have been 66 incidents reported through the first quarter of 2018, including 22 off the coast of Nigeria, according to International Chamber of Commerce's International Maritime Bureau (IMB).
That is up from 43 incidents during the same period last year and 37 in the first quarter of 2016.
Of the 66 piracy occurrences, 39 have been boardings, while four have been hijackings.
The rest have been attempted attacks, including 11 ships -- eight off Nigeria -- being fired upon.
A hundred crew were taken hostage and 14 were taken from their vessels as a result the 66 incidents, IMB states.
As a region, the Gulf of Guinea accounts for 29 of all occurrences and the four hijackings that took place during this year's first quarter.
There were 180 piracy incidents worldwide in 2017, down from 191 in 2016, according to IMB.
