On Friday, an Iranian diplomat and three other Iranian citizens went on trial in Belgium for reportedly conspiring to bomb a 2018 rally by an opposition group in exile, the Paris-based National Council Resistance of Iran (NCRI).

Vienna-based diplomat Assadolah Assadi and the other Iranians were charged by Belgian prosecutors with the suspected plot against the rally, where the keynote speaker was the U.S. The personal counsel of President Donald Trump, Rudy Giuliani.

In Germany, Assadi was detained while on vacation and handed over to Belgium.

He declined to appear in court on the first day of the trial in Antwerp and via his lawyer, requested diplomatic immunity.

"My client asked me to represent him today, he let me know he has the fullest respect for these judges but as he considers that he should benefit from immunity, they are not allowed to judge him."

Assadi was the third highest-ranking official at the Iranian Embassy in Vienna and according to French officials, in Southern Europe, he was in charge of intelligence.

Tehran consistently refuted the accusations, arguing that the claims were a "false flag" stunt by the NCRI, considered by Iran to be a terrorist organization.

This is the first time a European Union country has adjudicated a case involving an Iranian government official on terrorism charges.