European Union naval officials say Somali pirates have hijacked a Singapore-flagged container ship.

A statement on the Web site of the EU anti-piracy force says the Kota Wajar was seized early Thursday in the Indian Ocean about 300 miles north of the Seychelles islands.

The statement says coalition forces sent an aircraft to investigate.

It was not immediately clear how many crew were onboard or what their nationalities were.

Calls to naval officials went unanswered on Saturday.

Somalia has been ravaged by violence and anarchy since 1991 and piracy has flourished off its coast, making the Gulf of Aden one of the most dangerous waterways in the world.