The Ukrainian Airlines jet that crashed on Tuesday outside Tehran was shot down by an Iranian anti-aircraft missile, according to US media reports.
All 176 people on board were killed after the Boeing 737-800 crashed shortly after taking off from Tehran’s international airport on Tuesday.
US magazine Newsweek today said a Pentagon official, a senior US intelligence official and an Iraqi intelligence official said they believed the plane was hit by an Iranian missile.
The sources cited said the shooting down of the airliner was a mistake.
The report said the plane was struck by a Russia-built Tor-M1 surface-to-air missile system, known to NATO as Gauntlet.
The plane went down the same night that Iran fired a barrage of ballistic missiles at US military bases in Iraq, in retaliation for the killing of Revolutionary Guard Quds Force commander Major General Qassem Soleimani.
Ukraine said today it wanted to search the crash site for missile debris after seeing unverified images circulating on social media of fragments of a Tor-M1 missile at the scene.
Ukraine is looking at various possible causes, including a missile attack, a collision, an engine explosion or terrorism.
Videos show that the plane was on fire in the air before it crashed.
Iranian authorities initially blamed the crash on an unspecified technical problem.
Three Brits were among the 176 people killed in the disaster.
A total of 167 passengers and nine crew members were on the Ukraine International Airlines flight to Kiev.