There appears to be an element of mystery behind Wednesday morning’s crash of a Kievbound Ukranian airliner that was reduced to debris a few minutes after it took off from Tehran’s Imam Khomeini international airport, killing no fewer than 176 people, representing a cross-section of nationalities. Death knows no frontier; among the casualties were 82 Iranians, 63 Canadians, 11 Ukrainians, 10 Swedes, four Afghans, three Germans and three Britons.

As Iran lunges from crisis to crisis, this is the third tragedy that has convulsed the nation in the immediate aftermath of the US drone attack on a General of the Revolutionary Guards and the funeral stampede in which 56 people are said to have perished. A statement initially posted on the website of the Ukrainian embassy in Iran has ruled out an act of terror; the crash, it said, had been caused by an engine malfunction.

However, this was later redacted, with the embassy stating that all information would be provided by an official commission. The mystery has deepened with Iran saying it will not hand over the black box to the plane’s manufacturer, Boeing ~ a US company. The vital black box, that has critical records of how the plane crashed, was retrieved from among the debris that lay scattered in a field outside Tehran. Nor for that matter is it clear whether the Iranian authorities are disputing the legality of handing over the black box to Boeing or whether they are seeking to inspect the box themselves. Suffice it to register that the news has fuelled speculation that there was something suspicious about the downing of the plane.

There is no explanation yet as to why the takeoff was delayed. Boeing, which usually assists with such investigations, released a brief statement saying it was aware of media reports about the disaster and was gathering more information. Very little has been disclosed thus far, and the world would expect the stakeholders to be suitably explicit. The aircraft was scheduled to fly from one storm centre (Tehran) to another (Ukraine). So heartrending a catastrophe lends no scope for prevarication, let alone geostrategic hedging.

The 737-800 belongs to the same family but is different to the 737 Max 8 aircraft, which has been grounded since two fatal crashes occurred within six months in Indonesia and Ethiopia in 2018. The plane that crashed was less than four years old and had been checked two days before the accident, according to Ukraine International Airlines, which has indefinitely suspended flights to Tehran. Boeing, America’s largest manufacturing exporter, has struggled to regain public trust after its 737 Max plane was involved in the two crashes that killed 346 people. Since Wednesday there is much that is fogbound about the circumstances. As much is implicit in the Ukraine President, Volodymyr Zelenskiy’s order to conduct an investigation and a “sweeping check of all civilian aircraft” in the country.