Four bodies were found Friday morning after a US military aircraft with nine soldiers aboard crashed in central Albania on Thursday night, the ATA news agency reported.

"Albanian police and military forces assisted by residents of the area are searching for the other bodies," an Albanian State Police spokeswoman was quoted by the ATA as saying.

A US military MC130H was taking part in a joint exercise with Albanian forces when it crashed into Driza Mountain in the district of Gramsh, 100 km southeast of the capital Tirana.

"We are intensively continuing search operations but the conditions are very difficult," Albanian army Chief of Staff Lt. Gen. Pellumb Qazimi said on Friday.

The Albanian Defense Ministry said it has followed the situation closely.

Unconfirmed reports said the plane sent out signals for help before the crash which was likely caused by mechanical defect.