Iran admits it shot down Ukrainian passenger jet

Iran admits truth of Western claims that Ukraine International Airlines airliner was struck by an Iranian missile in a catastrophic error, as Tehran was on high alert for a potential US attack.

TEHRAN - Iran said on Saturday its armed forces "unintentionally" shot down a Ukrainian passenger jet that crashed after taking off from Tehran, killing all 176 people aboard.

President Hassan Rouhani said a military investigation had found "missiles fired due to human error" brought down the Boeing 737 on Wednesday, calling it an "unforgivable mistake".

The about-turn came after officials in Iran had categorically denied Western claims that the Ukraine International Airlines (UIA) airliner had been struck by a missile in a catastrophic error.

The plane, which had been bound for Kiev, slammed into a field shortly after taking off from Tehran's Imam Khomeini International Airport before dawn on Wednesday.

It came only hours after Iran's armed forces launched a wave of missiles at bases hosting American forces in Iraq in response to the killing of Qasem Soleimani, one of Iran's top generals, in a US drone strike.

Iran had come under mounting pressure to allow a "credible" investigation after video footage emerged appearing to show the plane being hit by a fast-moving object before a flash appears.

The Ukrainian and Canadian leaders called for accountability after Iran's admission.

The armed forces were first to acknowledge the error, saying the Boeing 737 had been mistaken for a "hostile target" at a time when enemy threats were at the highest level.

"The Islamic Republic of Iran deeply regrets this disastrous mistake," Rouhani said on Twitter.

"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."

In a statement posted on the government's website, Rouhani said Iran's armed forces had been on alert for possible attacks by the Americans after the "martyrdom" of Soleimani.

"Iran is very much saddened by this catastrophic mistake and I, on behalf of the Islamic Republic of Iran, express my deep condolences to the families of victims of this painful catastrophe," he said.

Rouhani added he had ordered "all relevant bodies to take all necessary actions (to ensure) compensation" to the families of those killed.

"This painful incident is not an issue that can be overcome easily."

He said "the perpetrators of this unforgivable mistake will be prosecuted".

"It is necessary to take necessary steps and measures to remove the weak points of the country's defence systems so that such a catastrophe is never repeated again."

The majority of passengers on UIA Flight PS752 were dual national Iranian-Canadians but also included Ukrainians, Afghans, Britons and Swedes.

Demands for justice

Ukrainian President Volodymyr Zelensky demanded Saturday that Iran punish those responsible for the downing of the plane and pay compensation.

"We expect Iran... to bring the guilty to the courts," the Ukrainian leader wrote on Facebook.

Canadian Prime Minister Justin Trudeau said closure and accountability were needed in the wake of the incident.

Trudeau also demanded "transparency, and justice for the families and loved ones of the victims".

"This is a national tragedy, and all Canadians are mourning together," his office said in a statement.

The disaster came as tensions soared in the region after the Soleimani killing, and fears grew of an all-out war between Iran and its arch-enemy the United States.

Washington said the Soleimani strike was carried out to prevent "imminent", large-scale attacks on American embassies.

Tehran had vowed "severe revenge" for the killing of Soleimani before launching missiles at the bases in Iraq.

Iran has invited the United States, Ukraine, Canada and others to join the crash investigation.

It is Iran's worst civil aviation disaster since 1988 when the US military said it shot down an Iran Air plane over the Gulf by mistake, killing all 290 people on board.

Video footage of the UIA 737, which The New York Times said it had verified, emerged and appeared to show the moment the airliner was hit.

A fast-moving object is seen rising at an angle into the sky before a bright flash appears, which dims and then continues moving forward. Several seconds later, an explosion is heard and the sky lights up.

Many airlines from around the world cancelled flights to and from Iran in the wake of the crash, or rerouted flights away from Iranian airspace.

Nations around the world have called for restraint and de-escalation, and fears of a full-blown conflict have subsided after US President Donald Trump said on Wednesday that Iran appeared to be standing down after targeting the US bases in Iraq.

'Shame on you'

Meanwhile, for some Iranians, the authorities' expressions of condolence were not enough after they spent days denying Western accusations that Iran was responsible for the crash.

The expressions of condolence over the incident from Supreme Leader Ayatollah Ali Khamenei and Rouhani failed to calm angry Iranians, who used social media to express their outrage against the establishment for concealing the truth.

"It is a national tragedy. The way it was handled and it was announced by the authorities was even more tragic," said Ali Ansari, a moderate cleric, according to Iran's semi-official ILNA news agency.

Many Iranians asked why authorities did not close down Tehran's airport and the country's airspace at a time when they would have been on alert for retaliation after the missile strikes on Iraqi military bases.

There were no fatalities in those strikes, with some reports suggesting that Iran had used back-channels to warn the Americans of the imminent missile launch, in order to ensure there were no casualties and avoid a military escalation.

"They were so careful not to kill any American in their revenge for Soleimani. But they did not close the airport? This shows how much this regime cares for Iranians," said Mira Sedaghati in Tehran by telephone.

An Iranian military statement carried by state media said the downing of the Ukrainian plane was a "human error and unintentional".

"Unintentionally? What does it mean? They concealed this huge tragic news for days just to mourn for Soleimani. Shame on you," said Reza Ghadyani, in Tabriz city.

The country held three days of funeral processions for Soleimani, who was head of the Revolutionary Guards' overseas Quds Force and a national hero. Hundreds of thousands of people participated across the country.

Some Iranians called for resignation of officials, dismissing their apologies.

"You took your revenge from Iranians," tweeted Ahmad Batebi on his @radiojibi Twitter account, in response to Rouhani's tweet saying that "The Islamic Republic of Iran deeply regrets this disastrous mistake".

"Only resignation," tweeted Sadeq on his @sadeq1367 account

In a Twitter message on Saturday, Foreign Minister Mohammad Javad Zarif cast some of the blame for the plane disaster on what he called US adventurism.

"Human error at time of crisis caused by US adventurism led to disaster," Zarif tweeted. "Our profound regrets, apologies and condolences to our people, to the families of all victims, and to other affected nations."

"It's the end line Mr. Minister! You ruined everything!," responded Bita Razaqi on @bitarazaqi.