For the Belgian prime minister Charles Michel, Sunday's 20km de Bruxelles race resulted in emergency medical treatment for damage to his hearing, according to The Guardian.

The Belgian King's youngest sister, Princess Astrid, accidentally fired the starting pistol too close to Michel's left ear, leaving him with an element of hearing loss, according to reports.

Michel, 41, had been assisting the Princess in starting the 38th edition of the annual 20km race.

Initially appearing to laugh the shock of the blast off, by Monday the prime minister reportedly sought medical treatment for his hearing. This resulted in Michel's schedule having to be cleared on Tuesday, which included giving evidence to a committee of the Belgian Parliament.

However, the rest of his scheduled has not been cleared and it was reported that Michel is attending work between doctor appointments.

“The prime minister must follow a number of treatments within 48 hours after the incident,” his spokesman, Barend Leyts, told reporters (via The Guardian). The Belgian royal family has not yet commented on the incident.

Belgian's annual race consisted of an estimated 40,000 runners and came a few days after Michel hosted US President Donald Trump and his wife Melania in Brussels on his foreign tour.