Ukraine's government has banned all flights from Iranian airspace following a deadly crash involving a Ukrainian International Airlines flight that went down shortly after departing Tehran, killing all 176 people on board.

The Washington Post reported Wednesday that aviation experts have yet to explain the reason for the deadly incident, with one aviation expert telling the newspaper that it looked as if the aircraft had come apart before hitting the ground.

“The wreckage pattern was very consistent with a plane that was not intact when it hit the ground,” Todd Curtis, a writer for Airsafe.com, told the Post. “I didn’t see a large central crater.”

ADVERTISEMENT

Iranian officials also said Wednesday that they would not turn over black box recordings from the crash to officials from Boeing or the Trump administration, while the Ukraine Embassy in Tehran reportedly took down an initial report ruling out terrorism or foul play in the crash.

A spokesman for Iran's armed forces reportedly denied that the plane was hit by rocket fire or other weaponry used by forces in the area.

"The rumors about the plane are completely false and no military or political expert has confirmed it,” Gen. Abolfazl Shekarchi told the Fars news agency, according to the Post.

Ukraine's president, Volodymyr Zelensky, said in a Facebook post that members of the media and others should avoid making unfounded theories about the crash.

“I implore you all to refrain from speculating and making uncorroborated theories in relation to the plane crash before any official statements are made,” he said according to a translation.