An Iranian military plane has crashed while taking off from an airport in Tehran, killing elite troops.
The plane crashed during take-off from Mehrabad airport
Iran's Revolutionary Guards said in a statement that 36 people on board the Russian-built Antonov-74 had been killed - 30 soldiers and six crew.
Two soldiers survived and were being treated in hospital, it added.
The commander of the Revolutionary Guards suggested to a local news agency that there may have been foul play, but he gave no further details.
The plane was due to fly from Mehrabad airport to the southern city of Shiraz but crashed at the end of the runway.
A representative of parliament's national security committee said the plane's right engine failed, causing the wing tip to touch the runway and explode.
The statement from the Revolutionary Guards said that the soldiers "were going to southern Iran on a mission".
The guards are the ideological wing of the Iranian military and are believed to have wide influence in the presidency of Mahmoud Ahmadinejad.
There were reportedly several senior officers on board the plane.
The BBC correspondent in Tehran says Iran has an appalling air safety record.
There have been a number of disasters in recent years - this is the fourth plane crash in less than a year.
Almost a year ago, a military transport aircraft crashed, killing 128 people.
That plane was attempting an emergency landing at Tehran airport when it hit a 10-storey building nearby.