Iran's Supreme Leader has offered condolences and called for an investigation after his military says it accidentally shot down a Ukrainian passenger plane.
All one hundred and seventy six people on board died when the aircraft came down after taking off from Tehran on Wednesday, against the backdrop of heightened US-Iran tensions.
Iranian forces say they mistook it for a hostile target, following a ballistic missile attack on two bases housing UK and US troops in Iraq.
The attack came after the US killed top Iranian General, Qassem Soleimani, in an air strike on Baghdad airport.
US military officials say they attempted to kill another high-ranking Iranian commander in Yemen, but their drone strike on Abdul Reza Shahla'i failed.
The country's government previously rubbished western accusations it was responsible.
In a statement, Iranian military officials said, "in such a condition, because of human error and in an unintentional way, the flight was hit."
It apologised and said it would upgrade its systems to prevent future tragedies.
Ukrainian President Volodymyr Zelenskiy said his nation needs "assurances" of a "full and open investigation, bringing the perpetrators to justice".
He added that Ukraine expected the "paying of compensation" and "official apologies through diplomatic channels".
Cover image: Wreckage at the site of a crash of an Iranian Boeing 737 jet about 30 miles south of Tehran, Wednesday (Picture: PA).