Regarding the downing of Ukraine International Airlines flight PS752 in January 2020, Iran is being sued at the International Court of Justice.
The families of the 176 people on board who died are suing on behalf of four countries: Canada, Sweden, Ukraine, and the United Kingdom.
After taking off from Tehran, a Revolutionary Guards air defense unit launched two missiles at the aircraft.
Iran acknowledged accidentally shooting down the plane three days later.
According to the Aerospace Force of the Revolutionary Guards, an air defense system mistook the Boeing 737-800 for a US missile.
Ten members of the armed forces were jailed by an Iranian court in April, but the victims' families deemed the sentences "meaningless and unacceptable.".
In their application to the International Court of Justice, the four countries whose citizens or residents perished in the incident claim that Iran "violated a series of obligations" under a convention on civil aviation by shooting down the plane.
They charge Iran with failing to take all reasonable precautions to stop the plane's downing, which occurred at a time of intense hostilities between Iran and the US.
Iran then allegedly failed to conduct a fair, transparent, and impartial criminal investigation and prosecution.
Iran must publicly acknowledge its "internationally wrongful acts," apologize to the families, and guarantee that they won't happen again, according to the countries' requests to the court.
The application also requests that the court "order full reparation for all injury caused," urging Iran to give the families of the victims "full compensation" and to return the victims' missing belongings.
The group asserted that Iran should submit to binding arbitration in December 2022 and that the missiles that hit the flight were launched "illegally and intentionally.".
The Iranian government had six months to respond, a spokesperson for Canada's foreign affairs ministry told the BBC at the time. Since this deadline has since passed, the nations are now considering taking legal action.