The rally was attended by an estimated 100,000 Iranians and hundreds of international dignitaries. A British Member of Parliament who attended said "Had the plot succeeded, it would have been the deadliest terror operation ever carried out in Europe. The US would undeniably have declared war on Iran – and it was only because the plot was foiled, world war three was averted." Belgian police had been informed of a possible attack on the rally, and found 550g (1lb 3oz) of explosive and a detonator in the car of Amir Saadouni and Nasimeh Naami. Saadouni, Naami, Assadi (believed to be the mastermind), and another Iranian went on trial in Antwerp on 27 November 2020. Court documents allege that Assadi was ordered by Iranian authorities to smuggle the explosives into Europe on a commercial flight, and give them to Saadouni and Naami, who were arrested two days later.