The plane, a turbo-propeller aircraft belonging to the national police, had seven people on board when it disappeared from radar in the restive Sistan-Baluchistan province, which borders Pakistan.
The plane had earlier left Tehran and the wreckage was discovered Sunday morning, the Fars news agency said, noting that the deputy of Iran’s police inspectorate was among the three officers killed.
The English-language Press TV station said that all seven on board the aircraft had died.
There were no details on the cause of the crash but the plane was found in a mountainous area and a border police commander told Fars that it had not been downed by a missile or other weaponry.
The police were heading to Sistan-Baluchistan’s provincial capital, Zahedan, to investigate attacks that have killed five members of Iran’s security forces since Wednesday.
Sistan-Baluchistan, which has a large Sunni Muslim community in an otherwise predominantly Shiite country, often sees violence involving Sunni extremists and drug smugglers.
Iran says the rebels enter its territory from Pakistan. -AFP