A military statement carried by state media on Saturday said the plane was mistaken for a "hostile target" after it turned toward a "sensitive military centre" of the Revolutionary Guard. The military was at its "highest level of readiness", it said, amid the heightened tensions with the United States. People inspect debris from the Ukrainian Airlines plane on the outskirts of Tehran. Credit:AP "In such a condition, because of human error and in an unintentional way, the flight was hit," the statement said. It apologised for the disaster and said it would upgrade its systems to prevent such "mistakes" in the future. It also said those responsible for the strike on the plane would be prosecuted. The plane, en route to the Ukrainian capital of Kiev, was carrying 167 passengers and nine crew members from several countries, including 82 Iranians, at least 57 Canadians and 11 Ukrainians, according to officials. The Canadian government had earlier lowered the nation's death toll from 63.

Iran's acknowledgement of responsibility for the crash was likely to inflame public sentiment against authorities after Iranians had rallied around their leaders in the wake of Soleimani's killing. The general was seen as a national icon, and hundreds of thousands of Iranians had turned out for funeral processions across the country. Rescue workers carry the body of a victim of the Ukrainian plane crash to a row of body bags, in Shahedshahr, south-west of Tehran, Iran, on Wednesday. Credit:AP But the vast majority of the plane victims were Iranians or Iranian-Canadians, and the crash came just weeks after authorities quashed nationwide protests ignited by a hike in gasoline prices. Iran's President Hassan Rouhani blamed the downing of the plane on "threats and bullying" by the US. He expressed condolences to families of the victims, and he called for a "full investigation" and the prosecution of those responsible. "A sad day," Iran's Foreign Minister Mohammad Javad Zarif tweeted along with a broken heart emoji. "Human error at time of crisis caused by US adventurism led to disaster. Our profound regrets, apologies and condolences to our people, to the families of all victims, and to other affected nations."

It comes as Canada's Foreign Affairs Minister Francois Champagne announced the creation of an international working group to press Iran for a thorough investigation into the crash. Champagne said the new International Co-ordination and Response Group included countries outside Iran who lost citizens - Iran, Sweden, Afghanistan, Ukraine, the United Kingdom - except Germany. The US promised "appropriate action" on Friday in response to its assessment that an Iranian missile was responsible for the crash. Loading Replay Replay video Play video Play video

Canadian Prime Minister Justin Trudeau on Friday blamed Iran for shooting the plane down with a surface-to-air missile. He said it might have been an accident triggered by hostilities in the Middle East. "This is the right step for the Iranian government to admit responsibility, and it gives people a step toward closure with this admission," said Payman Parseyan, a prominent Iranian-Canadian in western Canada who lost a number of friends in the crash. "I think the investigation would have disclosed it whether they admitted it or not. This will give them an opportunity to save face." Iran's acknowledgement of responsibility was likely to renew questions of why authorities did not shut down the country's main international airport and its airspace after the ballistic missile attack, when they feared US reprisals. It also undermines the credibility of information provided by senior Iranian officials. As recently as Friday, Ali Abedzadeh, the head of the national aviation department, had told reporters "with certainty" that a missile had not caused the crash.