An Iranian passenger plane crashed into a mountainous area in the central part of the country on Sunday killing all 66 people on board, said media reports, citing a spokesman for Iran's Aseman Airlines.

The plane was flying from Tehran to the southern Iranian city of Yasuj, some 485 miles south of the Iranian capital, reported BBC.

The ATR-72, a twin-engine turboprop used for short-distance regional flying, went down near the remote mountain town of Semirom, 620 km south of capital Tehran, stated the report citing Aseman Airlines spokesman Mohammad Taghi Tabatabai.
 
The flight, which crashed at Mount Dena, was carrying 60 passengers, including one child, and six crew members, Tabatabai told state TV.

"All emergency forces are on alert," an emergency services spokesman said.

Due to foggy condition, rescue helicopters couldn't reach the crash site in the Zagros Mountains, state TV reported.

The Iranian Red Crescent said it has deployed to the area, which was quite foggy at the time of the crash. Authorities said they would be investigating, it added.