Australia’s Prime Minister said he has received intelligence that shows Iran shot down the Ukrainian International Airlines flight that crashed on Wednesday.

Morrison’s comments come after Canadian Prime Minister Justin Trudeau revealed he had received intelligence that the jet that crashed in Tehran – killing all on board – was shot down by Iran.

The Boeing 737-800 was travelling from Iran to Ukraine with 176 people on board, including nine crew members, when it crashed within minutes after take-off. Among them were 63 Canadians.

Speaking to the press, Trudeau said Canadian and allied intelligence supports the theory that the plane was shot down by an Iranian surface-to-air missile. He emphasised that it may well have been “unintentional”.

“Our government will continue to work closely with its partners to ensure this crash is thoroughly investigated. Canadians have questions and they deserve answers,” Trudeau said.

The crash came just hours after Iran launched a missile strike targeting two Iraqi military bases housing United States forces, in retaliation for the killing of one of Iran’s top generals, Qassem Soleimani, last week.

Prime Minister Scott Morrison confirmed Australia had received the same intelligence as other countries, and told ABC News that “It does not suggest that this was intentional”.

Morrison added that he had spoken to Trudeau about any support Australia could provide. “If there’s anything we can do to assist then of course we will,” he told AM.

Iran denies “illogical rumours”

United States President Donald Trump on Thursday (local time) said he suspected the crash was not due to mechanical issues and indicated “somebody could have made a mistake on the other side”.

The head of Iran’s Civil Aviation Organization, Ali Abedzadeh, denied what he described as “illogical rumours” that the airliner had been hit by a missile.

“Scientifically, it is impossible that a missile hit the Ukrainian plane, and such rumours are illogical,” Abedzadeh said, as reported by Iranian news agency ISNA.

Speaking to CNN, Abedzadeh said that once the plane took off, it flew for five minutes and “the pilot tried to return to the airport but failed”.

He further questioned how a plane could be hit by “a rocket” and then the pilot, “try to turn back to the airport?”

British Prime Minister Boris Johnson has also announced a “body of information” indicated the flight was shot down, perhaps unintentionally.

Three British citizens were among those killed in the crash of UIA Flight PS752.

“We are working closely with Canada and our international partners and there now needs to be a full, transparent investigation,” Johnson said in a statement.

Iran says it will not send black boxes to Boeing

Amid heightened tensions between the United States and Iran, Tehran has reportedly indicated it will not hand over flight recorders to the US for investigation, Reuters reported.

Ukrainian aviation experts have arrived in Tehran, and began decoding data from Flight PS752 on Thursday, according to Abedzadeh, as reported by CNN.

But if the available equipment “is not enough to get the content” from the boxes, Iran will outsource them to “the experts from France or Canada”, Abedzadeh said, and not to Boeing.

According to the 1944 Chicago Convention on International Civil Action, the responsibility of investigations is assigned to the countries where aircraft incidences occur.

Iran, therefore, is responsible for overseeing the current investigation, according to the Chicago Convention. However, the country that manufactured the aircraft – the United States – and the country of the airline that operated the plane are also entitled to have representatives involved in the probe.

The Chicago Convention also allows the country responsible for the investigation to let another country take charge of a probe.

The aircraft’s manufacturer, Boeing, said it stands ready to assist in any way needed.

“This is a tragic event and our heartfelt thoughts are with the crew, passengers, and their families,” Boeing tweeted. “We are in contact with our airline customer and stand by them in this difficult time.”

At Ukraine’s Boryspil airport, flowers and candles have reportedly been laid out in front of portraits of the crew killed in the crash.

“I knew them all,” UIA pilot Artem, who laid a bouquet of red roses, told AFP news agency.