Iran has admitted “unintentionally” shooting down a Ukrainian passenger jet, killing all 176 people on board.
An investigation found that “missiles were fired due to human error”, President Hassan Rouhani said. He described the crash as an “unforgivable mistake”.
The military said the jet turned towards a sensitive site belonging to Iran’s Revolutionary Guards and was then mistaken for a cruise missile.
Iran had previously rejected suggestions that it was to blame.
The downing of Ukraine International Airlines flight PS752 on Wednesday came just hours after Iran carried out missile strikes on two airbases housing US forces in Iraq.
The strikes were a response to the killing of senior Iranian commander Qasem Soleimani in a US drone strike in Baghdad on 3 January.
Iran initially denied reports that one of its missiles had brought down the Ukrainian plane near the capital, Tehran. But pressure quickly mounted after Western intelligence officials said evidence pointed to Iranian involvement.
The Ukrainian flight, which was en route to Kyiv, came down near Imam Khomeini Airport shortly after take-off. Victims included dozens of Iranians and Canadians, as well as nationals from Ukraine, the UK, Afghanistan, and Germany.
On Saturday morning, an Iranian military statement read on state TV announced that it had struck flight PS752 with a missile by mistake.
It said the plane had turned towards a “sensitive military centre” of the Revolutionary Guards, a force set up to defend the country’s Islamic system. The statement said it had the “flying posture and altitude of an enemy target”.
Because of heightened tensions with the US, Iran’s military “was at its highest level of readiness”, the statement added. “In such a condition, because of human error and in an unintentional way, the flight was hit.”
The military apologised for downing the plane, saying it would upgrade its systems to prevent such “mistakes” in the future. It added that those responsible would be held accountable and prosecuted.
Brig-Gen Amir Ali Hajizadeh, the Revolutionary Guards aerospace commander, said the force took “full responsibility” for the crash.
He said a request had been made for a no-fly zone in the area before the incident but – for reasons that are unclear – this was rejected.
Gen Hajizadeh also said the aircraft was shot down by a short-range missile that exploded next to it. He said he informed the authorities about what had happened on Wednesday, days before Iran publicly admitted its involvement.
Iran’s Supreme Leader Ali Khamenei ordered the military to investigate “the possible shortcomings or mistakes” that led to the crash.
In a statement, he said there was “proof of human error” and confirmed that he had “requested the relevant authorities to take necessary measures to prevent” it happening again.
Foreign Minister Javad Zarif apologised to the families of the victims but laid part of the blame on the US. “Human error at a time of crisis caused by US adventurism led to this disaster,” he said.