An Iranian commercial airliner with 66 people on board crashed with no survivors on Sunday in the central province of Isfahan, Iran's Aseman Airlines confirmed.
The company's public relations department announced that all 60 passengers, including a child, as well as the two pilots, two copilots and two security personnel were killed.
The plane, an ATR 72 twin-engine turboprop that had been in operation for two decades, disappeared from radar 20 minutes after taking off from Tehran and heading toward the southeastern city of Yasuj, the official ISNA news agency cited a spokesman for the Iranian emergency services, Mojtaba Khaledi, as saying.
The accident is believed to have been caused by bad weather conditions recorded in the region, in particular fog and wind.
Authorities sent helicopters to the scene of the crash, as the mountainous terrain made access by ambulances difficult.
The plane crashed into a mountain known as Dena near the city of Semirom, located in the south of Isfahan province.
Iran has an outdated commercial air fleet due to years of international sanctions imposed on the country, with several serious accidents in the previous decade.
The most recent plane crash killed 40 people in Aug. 2014 in Tehran; three years earlier, 78 people were killed when their plane was brought down during a storm in northern Iran.