Forensics experts are working to identify body parts recovered in waters where an Indonesia police plane with 13 people aboard is believed to have crashed on Saturday, authorities said Sunday.

The N-28 Skytruck was flying from Pangkalpinang on Bangka Island, east of Sumatra, to Batam Island, near Singapore, Saturday morning when air traffic controllers in Singapore lost contact with the plane.

Fishermen later found aircraft debris including seats and documents of the aircraft, as well as body parts in waters near Batam.

"The identification process is still ongoing," said Djarot Wibowo, chief of the police forensic team in Riau Islands Province, which covers Batam.