Air Force spokesman Capt. Gihan Seneviratne, said a Chinese built Y-12, crashed in the Haputale district, some 200 kilometres east of the capital Colombo.
Two pilots and two other crewmembers were on the Chinese-built Y-12 aircraft, which was on an observation mission.
The Derana television channel reported a woman at the scene where the aircraft crashed sustained injuries and was receiving treatment at a hospital.
According to Dpa, it was not immediately clear what caused the crash.
Investigations has commenced while initial reports said that adverse weather with misty conditions in the mountains area may have contributed.
The incident occured one day after a plane carrying Sudanese judges and army offices crashed in the Darfur region of Sudan. All on board were killed.
