Iran said on Saturday it had mistakenly shot down a Ukrainian plane killing all 176 aboard and voiced deep regret, after initially denying it brought down the aircraft in the tense aftermath of Iranian missile strikes on U.S. targets in Iraq.

“The Islamic Republic of Iran deeply regrets this disastrous mistake,” Iranian President Hassan Rouhani wrote on Twitter, promising those behind the incident would be prosecuted. “My thoughts and prayers go to all the mourning families.”

Wednesday’s crash heightened pressure on Iran after months of friction with the United States and tit-for-tat attacks. A U.S. drone strike had killed an Iranian general in Iraq on Jan. 3, prompting Tehran to fire at U.S. targets on Wednesday.

Canada, which had 57 citizens on board, and the United States both said they believed an Iranian missile brought down the aircraft although they said it was probably an accident. Canada’s foreign minister had told Iran “the world is watching.”

Responding to Iran’s U-turn, Ukraine’s President Volodymyr Zelenskiy said he wanted an official apology and full cooperation, demanding those responsible to be held to account.

Experts said mounting international scrutiny would have made it all but impossible to hide signs of a missile strike in an investigation and Iran may have felt a swift policy reversal was better than battling rising criticism abroad, as well as facing growing anger and grief over the crash at home.

Iran’s Foreign Minister Mohammad Javad Zarif wrote on Twitter that “human error at time of crisis caused by U.S. adventurism led to disaster,” citing an initial armed forces investigation into the crash of the Boeing 737-800.

An Iranian military statement, the first to indicate Iran’s shift in position, said the plane had flown close to a sensitive military site belonging to the elite Revolutionary Guards.

It said that, at the time, planes had been spotted on radar near strategic sites which led to “further alertness” in air defense units, adding that responsible parties would be referred to a judicial department in the military.

Ukraine’s Foreign Minister Vadym Prystaiko had said on Friday that the plane was following a normal flight corridor. Experts said a probe would almost certainly have shown up tell-tale holes and other signs on the remains of the fuselage that a missile was to blame for the incident.

“There’s nothing you can do to cover it up or hide it,” said Anthony Brickhouse, an air safety expert at Embry-Riddle Aeronautical University and former U.S. National Transportation Safety Board investigator. “Evidence is evidence.”

The White House did not immediately respond to a request for comment.

Mobile phone footage posted and circulated by ordinary Iranians on Twitter after the crash had indicated that it came down in a ball of flames and exploded as it struck the ground.

Iran had said on Thursday it would download the information from voice and flight data recorders, known as black boxes, to determine what had happened, although it had said the process could take one to two months.
News Credit: Reuters