All 66 passengers and crew on an Iranian plane that crashed in a mountainous area of central Iran on Sunday are believed to be dead, state television quoted the airline's spokesman as saying.

"Aseman Airlines public relations head said that all on board are unfortunately dead," the television reporter said, without elaborating on how he obtained the information.

The plane crashed in central Iran during a flight from Tehran to the city of Yasuj in the southwest of the country, Iranian media reported.

The ATR-made plane operated by Iranian carrier Aseman Airlines crashed in a mountainous area near the town of Semirom, news agency ISNA quoted emergency services spokesman Mojtaba Khaledi as saying.

Semirom's governor said rescue helicopters were unable to land in the crash site because of heavy fog and emergency workers were trying to reach the area by land, the semi-official Mehr news agency reported.

State-run PressTV said 66 people were on board the plane, which disappeared from radar screens 50 minutes after taking off from Tehran's 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 US sanctions have long prevented it from buying new aircraft or spare parts from the West.