A small military passenger jet crashed in northwestern Iran on Monday, killing the commander of the ground forces of the elite Revolutionary Guards and at least 12 other people, official media reported. It was the second time in two months that a military plane has crashed in Iran. On both occasions, the planes were carrying passengers and attempting to make an emergency landing. In Monday's crash, the plane, a Falcon of the Revolutionary Guards, was trying to make an emergency landing at Oroumieh, 900 kilometers (560 miles) northwest of the capital, Tehran, state television reported. The plane crashed because its landing gear jammed, preventing the wheels from being fully deployed, the official Islamic Republic News Agency reported. "Gen. Ahmad Kazemi, commander of the ground forces of the elite revolutionary guards, and other 10 officers of the Guards were killed," the agency quoted Guards' spokesman Gen. Masoud Jazayeri as saying. "The authorities are investigating the incident." State television said the plane's crew of two were also killed. However, the news agency and state radio said there were three crewmen. The discrepancy could not be immediately explained. State media did not say explain why the plane was approaching the airport for an emergency landing. The Falcon, which is made by the French company Dassault, is the preferred aircraft of high-ranking military officers in Iran. Gen. Kazemi, a veteran of the 1980-88 war with Iraq, was appointed commander of the Guards' ground forces in August in a reshuffle after President Mahmoud Ahmadinejad took office. In Iran, the Revolutionary Guards are a separate organization to the regular armed forces. Founded after the 1979 Islamic Revolution, the Guards have their own air, naval and ground components. President Ahmadinejad is a former commander in the Guards. On Dec. 6, a military transport plane crashed into a 10-story building near Tehran's Mehrabad airport, killing 115 people. The plane, a US-made C-130, had suffered engine trouble and the pilot was returning to the airport when the aircraft suddenly lost height and slammed into the apartment building. Most of the passengers were Iranian journalists. Iran has a history of aircraft accidents involving a heavy loss of life. The government has blamed the US trade embargo which makes it impossible for Iran to buy parts for its old US-built aircraft. But critics have also said planes are poorly maintained.