Sixty-six passengers and crew are feared dead in the crash of an Iranian Aseman Airlines ATR-72-212, performing flight EP-3704 from Tehran Mehrabad to Yasuj in Iran.
According to Aviation Herald, the aircraft disappeared from radar near the Zagroz Mountains at about 08:45L (05:15Z).
The wreckage was later found near the village of Semirom at an elevation between 12,500 and 13,500 feet.
The ATR 72 was built in1993 and the airline has blamed weather conditions.
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The airline initial reported there were no survivors found at the crash site but later retracted that statement.
It said: "Given the special circumstances of the region, we still have no access to the spot of the crash and therefore we cannot accurately and definitely confirm the death of all passengers of this plane."
The Red Crescent deployed search and rescue teams to the site.
Sixty passengers, two security guards, two flight attendants and the pilot and co-pilot were on board.
Bad weather has hampered rescue efforts and emergency teams have had to travel to the crash site by land rather than helicopter.
Aseman Airlines has suffered eight crashes since 1990, three of which have been fatal.
The other two were in August 2008 when a Boeing 737, EX-009, crashed near Bishkek-Mana, in Kyrgyzstan killing 65 of the 90 aboard.
And in October 1994 a Fokker F-28, EP-PAV, crashed near Natanz killing all 66 on board.
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