Iranian state TV said the plane was a Falcon jet, which belonged to the elite Revolutionary Guards. It crashed on Monday while attempting an emergency landing near Oroumieh, 900km northwest of the capital, Tehran.
A police spokesman said: "There were 13 on board, unfortunately all were killed."
Ahmad Panahi, head of Iran's Emergency Centre, was quoted as saying by the Fars news agency that the head of the ground forces of the Revolutionary Guard was among those killed
"Ahmad Kazemi was killed with 12 of his deputies and accompanying officers," he said.
Fars news agency put the total number of people on board the plane at 15, of whom 13 were definitely killed.
Mehr news agency said the crash was due to bad weather in snowbound northwest Iran. It said several high-ranking Revolutionary Guard commanders had been on board.
The accident is Iran's second in two months.
In December, 115 people were killed when a military transport aircraft crashed into a 10-storey apartment building near Tehran's Mehrabad airport.
Iran has a history of aircraft accidents involving a heavy loss of life.