A Greek-owned ship has been attacked by pirates off the coast of Somalia.
The fate of the crew members - who are said to be of Filipino origin - is not known, reported BBC.
According to an official at the International Maritime Bureau (IMB), the ship was hijacked by armed pirates on its way to Kenya.
Pirates operating out of war-torn Somalia regularly attack vessels using the major commercial shipping routes off the country's waters.
The threat of hijack and robbery has hampered the delivery of much-needed aid to people affected by the conflict.
The Greek vessel is the 13th ship seized by pirates off Somali waters in the last two months, Noel Choong of the IMB told the Associated Press news agency.
He said this latest attack indicated that Somali pirates had expanded their area of operations southwards from the Gulf of Aden, targeting vessels off the coast of Mogadishu.
A multinational naval force patrolling the area had been informed of the attack, Mr Choong said.
Earlier this week, French commandos rescued two sailors who were being held for ransom by pirates believed to be based in the port of Eyl in Somalia's Puntland region.
Somalia has been without a functioning central government for 17 years and has suffered from continual civil strife.
Battles between Islamist insurgents and Ethiopian-backed government soldiers have forced hundreds of thousands of people from their homes in the last 18 months.