Iran has admitted it “unintentionally” shot down a passenger jet, killing all 176 on board, in a stunning turnaround of its earlier denials of responsibility.

Iran’s president Hassan Rouhani on Saturday tweeted that “human error” was responsible for the “horrific crash” of the Ukraine International Airlines flight PS752 on Wednesday, shortly after taking off from Iran’s capital Tehran.

He expressed his “sincerest condolences” to all the families of the victims’ – most of whom were dual national Iranian Canadians but included Ukrainians, Afghans, Britons and Swedes – and deep regret for the “disastrous mistake”.

“Armed Forces’ internal investigation has concluded that regrettably missiles fired due to human error caused the horrific crash of the Ukrainian plane & death of 176 innocent people,” the president wrote on Twitter.

“Investigations continue to identify & prosecute this great tragedy & unforgivable mistake. #PS752

“The Islamic Republic of Iran deeply regrets this disastrous mistake.

“My thoughts and prayers go to all the mourning families. I offer my sincerest condolences.”

The Islamic Republic of Iran deeply regrets this disastrous mistake.

My thoughts and prayers go to all the mourning families. I offer my sincerest condolences. https://t.co/4dkePxupzm

— Hassan Rouhani (@HassanRouhani) January 11, 2020

After issuing the tweet, Mr Rouhani followed up with a lengthy statement in which he said the perpetrators of this “unforgivable mistake” would be prosecuted.

“Further investigation is needed to identify all the causes and roots of this tragedy and prosecute the perpetrators of this unforgivable mistake and inform the honourable people of Iran and the families of the victims about it,” the statement said.

“It is also necessary to adopt the required arrangements and measures to address the weaknesses of the country’s defence systems to make sure such a disaster is never repeated.”

Mr Rouhani said Iran’s Armed Forces had mistakenly shot down the plane while on “full alert” to possible US attacks following the “martyrdom” of General Qasem Soleimani who had been killed by the Americans.

He said the Iran army had been poised to defend itself in “the atmosphere of threats and intimidation by the aggressive American regime against the Iranian nation” when the missile wrongly targeted the plane.

Mr Rouhani said he had ordered all necessary measures to compensate and sympathise with the bereaved families, many of whom were Iranian.

“I also express my deep condolences and sympathy of the Iranian government to the nations, governments and families of non-Iranian victims” the statement said.

“This painful accident is not something that can be easily overlooked.”

Canada’s president Justin Trudeau reacted to Iran’s dramatic admission saying his government expected “full co-operation from Iranian authorities” to ensure “a complete and thorough investigation”.

“Our focus remains closure, accountability, transparency, and justice for the families and loved ones of the victims,” Mr Trudeau’s statement said.

“This is a national tragedy, and all Canadians are mourning together.”

Ukraine’s president Volodymr Zelinksy also demanded justice, saying in a statement his country wanted a “full and open investigation” to be conducted without delays and obstacles.

Earlier

In a statement on Iranian TV on Saturday, the military blamed “human error” for accidentally firing a surface-to-air missile earlier this week which brought down the Boeing 737-800, killing all 176 passengers and crew.

According to The Associated Press, the “military statement” said the Ukraine International Airlines flight PS752 was mistaken for a “hostile target” after it turned toward a “sensitive military center” of the Revolutionary Guard.

The military was at its “highest level of readiness” amid the heightened tensions with the United States, AP said.

“In such a condition, because of human error and in a unintentional way, the flight was hit,” the statement said, and apologised for the disaster saying it would upgrade its systems to prevent future tragedies.

It said those responsible for the strike on the plane would be prosecuted.

A sad day. Preliminary conclusions of internal investigation by Armed Forces:

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.
💔

— Javad Zarif (@JZarif) January 11, 2020

“A sad day,” Iran’s Foreign Minister Mohammad Javad Zarif tweeted on Saturday afternoon.

“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.”

Relatives, colleagues, and friends of crew members of the flight which crashed near Tehran lay flowers and light candles at Boryspil International Airport in Kiev, Ukraine. Photo: AAP

Earlier on Friday, the country’s head of civil aviation denied reports Iran was to blame as “illogical rumours”.

“Scientifically, it is impossible that a missile hit the Ukrainian plane and such rumours are illogical,” the semi-official ISNA News Agency quoted Ali Abedzadeh as saying.

But then the US and Canada, citing intelligence, said they believed Iran shot down the aircraft.

Dramatic footage emerged on Friday afternoon, verified by The New York Times, which appeared to show a small explosion mid-air over Parand, a city near the airport, with plane continuing to fly for several minutes before crashing.

It then crashed on the outskirts of Tehran during takeoff just hours after Iran launched a barrage of missiles at US forces in neighbouring Iraq.

The plane, en route to the Ukrainian capital of Kiiv, was carrying 167 passengers and nine crew members from several countries, including 82 Iranians, 63 Canadians and 11 Ukrainians, according to officials.

Canadian Prime Minister Justin Trudeau told reporters on Friday morning (Australian time) he had received intelligence the plane was shot down by an Iranian missile.

“The evidence indicates that the plane was shot down by an Iranian
surface-to-air missile. This may well have been unintentional,” he said.

“This new information reinforces the need for a thorough investigation into this matter.”

Prime Minister Scott Morrison told the ABC a few hours later Australia had received the same intelligence as the US and Canada and, “it does not suggest that this was intentional”.

–with agencies