A recent major oil spill off Estonia's northwestern coast has damaged the marine ecosystem in the Baltic Sea and its delicate bird population, authorities said.

The spill was located in the coastal areas of Laane and Harju counties, some 100 km southwest of the capital, Tallinn. It was caused by an unidentified ship, which might have deliberately leaked the oil, according to Estonia's environment ministry.

The spill could kill as many as 35,000 birds