A police plane crashed late on Saturday in the mountains outside Zahedan, the capital of the southeastern province of Sistan and Baluchestan.
The plane, a twin-engine turboprop Commander aircraft, was carrying high-ranking officers to Sistan and Baluchestan Province that borders Pakistan and Afghanistan, IRNA reported.
Police chief Brigadier General Esmaeil Ahmadi Moqaddam said, "The officers were traveling from Tehran to investigate the latest (terrorist) incidents in the province," the Mehr news agency reported on Sunday.
Ahmadi Moqaddam said the plane lost contact with the air traffic control tower nearly three hours after takeoff.
Two generals, including Mahmoud Sadeqi, a senior officer in charge of investigations, and two police officers were killed in the incident. Three crew members also lost their lives.
The wreckage of the aircraft was found the following day but the cause of the crash remains unknown, IRNA said.
The police chief added, "The pilot apparently wanted to make an emergency landing and chose a flat stretch of land for landing."
He cited poor visibility and darkness as an apparent cause of the crash.
