Iran is facing fresh pressure to give a full accounting of what happened to the Ukrainian Airlines plane that was shot down over its capital city last week with 176 people on board.
Ministers from five countries that lost citizens in the crash are gathering in London to demand answers.
Ahead of the meeting, Canada’s foreign minister said his country would “get to the very bottom” of what happened.
Iran has said the plane was brought down by a missile fired in error.
The plane, travelling to the Ukrainian capital Kyiv and carrying many passengers on their way to Canada, was downed amid escalating tensions between Iran and the US. There were no survivors.
Hours before, Iranian missiles had targeted two airbases in Iraq housing US forces.
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For three days after the tragedy Iran denied any responsibility but after international pressure, the hardline Revolutionary Guards accepted responsibility, saying the plane had been mistaken for a “cruise missile”.
The crisis has come at an extremely sensitive time for Iran, both in terms of its relationship with the international community and at home, where there have been anti-government protests.
What’s the meeting in London about?
Five countries who had citizens on the plane – Canada, Britain, Ukraine, Sweden and Afghanistan – have formed a new group to co-ordinate their response as the Iranian-led investigation unfolds.
Their foreign ministers planned to light memorial candles at the Canadian High Commission in London on Thursday to honour the dead before holding discussions focusing on the need for transparency from Iran.