An Iranian plane on Sunday crashed in southwest Iran, with all 60 passengers and 6 crew members on board believed to be dead, local media reported.

The plane crashed near the remote mountain town of Semirom in the Zagros Mountains, about 620 kilometers (390 miles) south of the capital, Tehran, the Fars news agency reported.

"This plane has crashed in the Semirom area and all emergency forces are on alert. The plane had 50 to 60 passengers," Pir Hossein Koolivand told Fars.

The plane was reportedly an ATR-72 that was flying from Tehran to the southwestern Iranian city of Yasuj.

The plane crashed into Dena mountain, part of the Zagros moutain range, around 23 kilometres (14 miles) from Yasuj, some 500 kilometers south of the capital, Mohammad Tabatabai, director of public relations for the airline, told state broadcaster IRIB.

Authorities said the plane was flown by Aseman Airlines, a semi-private air carrier headquartered in Tehran that specializes in flights to remote airfields across the country. It also flies internationally.