A Boeing 737 plane crashed shortly after takeoff from Imam Khomeini Airport in Tehran early Wednesday killing all 170 people on board, Iranian media and Red Crescent reported.
Early reports indicate that the Ukraine International Airlines plane may have crashed due to technical difficulties.
The plane was bound for Kiev, Ukraine.
It crashed about eight minutes after takeoff, flight tracking websites indicate.
Local media reported that ambulances were sent to the crash site.
“The fire is so heavy that we cannot (do) any rescue... we have 22 ambulances, four bus ambulances and a helicopter at the site,” Pirhossein Koulivand, head of Iran’s emergency services, told the state television IRNA.
“Obviously it is impossible that passengers are alive,” the head of Red Crescent told semi-official news agency ISNA, adding that 170 passengers and crew had boarded the plane.
Reza Jafarzadeh, a spokesman for Iran’s Civil Aviation Organisation, also put the number of passengers on board the flight at 170.
According to air tracking service FlightRadar24, the plane that crashed was on Flight PS 752.
Boeing said the company was aware of media reports of a plane crash in Iran and was gathering more information.
There were no suggested links between the crash and Iran's Wednesday morning missile strikes on American bases in Iraq.