Iran’s Revolutionary Guards shot down the Ukraine International Airlines flight on Jan. 8, 2020 shortly after it took off from Tehran Airport in what Iranian officials said at the time was a “disastrous mistake”.

In their application to the ICJ, also known as the World Court, the four countries said Iran had violated “a series of obligations” against the so-called Montreal Convention, aimed at securing the safety of civilian air travel.

They said Iran had failed to take all practicable measures to prevent the downing of Flight PS752 and had failed to conduct an impartial, transparent and fair criminal investigation and prosecution.

Most of the people killed in the crash were citizens of the four countries, which created a coordination group aiming to hold Iran to account.

Iran says its forces accidentally shot down the Boeing 737 jet at a time when tensions were high between Tehran and Washington, and a final report issued in 2021 blamed a misaligned radar and an error by an air defence operator.

Canada at the time said the report made “no attempt to answer critical questions about what truly happened”. Ukraine called it a cynical attempt by Iranian authorities to cover up the true reasons for the crash, which it said it suspected was intentional.

According to Iran’s claim, released by the court, Canada’s actions violate its state immunity enshrined in international law.

The move at the ICJ, also known as the World Court, comes a little over a week after the Canadian government announced it imposed sanctions on Iranian judges over alleged human rights abuses on top of longer-standing sanctions targeting Tehran.

Canada cut diplomatic ties with Iran in 2012 and listed the country as a supporter of terrorism.

Last year an Ontario court awarded C$107 million ($83.94 million), plus interest, to the families of six people who died when the Iranian Revolutionary Guards downed a Ukraine International Airlines plane near Tehran in 2020, killing all 176 people onboard.