Davide B tanker belongs to Dutch company De Poli Shipmanagement.
The remaining six crew members stayed aboard the vessel. The citizenship of captured people is unknown yet.
"Currently, the company's top priority is to set contacts wirth the missing team to provide their quickest and safe release. The emergency rapid response group keeps contact with all the authorities that were notified immediately after the incident. The company is in close contact with the families of sailors", reads the statement by De Poli Shipmanagement.
Ukraine's Foreign Ministry has not commented on the incident yet.
On Saturday, January 30, Nigerian pirates freed six Ukrainian sailors, the crew members of the Stevia cargo ship.