A private Turkish plane flying from the United Arab Emirates to Istanbul crashed on Sunday in the south of Iran with 11 people on board, Iranian state television reported.
Other Iranian media said the plane went down in a remote mountain in the snow-capped Zagros range during bad weather.
The plane had left from the emirate of Sharjah and went down near the city of Shahr-e Kord, about 400 kilometres (250 miles) south of Tehran, state television reported.
The aircraft was a Canadian-made Bombardier, according to the Iranian news agency Tasnim.
It had eight passengers and three crew members on board, said Reza Jafarzadeh, head of the Iran Civil Aviation Organization.
The cause of the crash was not immediately clear.
Tasnim quoted an ICAO official as saying: "The plane is on fire. After the pilot asked to lower altitude, it disappeared from the radar."
Turkey's NTV channel, quoting the Turkish transport ministry, said the plane belonged to the Istanbul-based Basaran Holding Company which is active in the energy, construction and tourism sectors.
Iranian media reported that rescuers had been dispatched by land to the crash site, which is located in a relatively isolated area Helen's Mountain -- a protected area in the Zagros range.
Some reports said the plane went down during heavy rain.
The head of Iran's Red Crescent, Morteza Salimi, told state television that two helicopters would fly to the area on Monday morning "to search for the plane's debris and bodies" -- indicating there could be no survivors.
The Zagros range was the scene of another aviation tragedy in February, when an ATR-72 twin engine passenger plane of Iran's Aseman Airlines crashed there killing all 66 people on board.
The plane had disappeared from radar after taking off from Tehran on a domestic flight as a snowstorm battered the mountains.
Rescue teams had to battle bad weather for days before they were able to recover the black boxes of that aircraft and had to interrupt their operation several times because of bad weather.
They are still working on bringing the remains of those killed down the valley from the crash site which lies at a height of about 4,000 metres (13,000 feet).