All 66 passengers and crew aboard a plane that crashed in central Iran on Sunday were believed to have been killed, state media reported.
The plane operated by Iranian carrier Aseman Airlines crashed in a mountainous area near the town of Semirom after taking off from Tehran's Mehrabad airport, news agency ISNA quoted emergency services spokesman Mojtaba Khaledi as saying.
The ATR-made plane was on a flight to the southwestern city of Yasuj and a spokesman for the airline said there were 60 passengers and six crew aboard.
"Aseman Airlines public relations head said that all on board are unfortunately dead," a reporter on state television said.
Rescue helicopters were unable to land at the crash site because of heavy fog and emergency workers were trying to reach the area by land, the semi-official Mehr news agency quoted the governor of Semirom as saying.
The leader of a rescue team told state television they had not reached the site of the crash yet.
Media reports said the plane disappeared from radar screens 50 minutes after taking off from Mehrabad airport.
Mehrabad is located in western Tehran and mainly functions as a domestic airport, although it also serves some international routes.
Iran has suffered several plane crashes in the past few decades. Tehran says U.S. sanctions have long prevented it from buying new aircraft or spare parts from the West.