Story highlights Charles Michel, Prime Minister of Belgium, is being treated for an ear injury

Michel was standing nearby when a starter pistol was fired Sunday at a Brussels road race

(CNN) It was supposed to be one of those routine ceremonial appearances that politicians make all the time.

Show up at a 20K race, wave to the crowd and cheer as the runners bolt from a starting line and dash through the streets of Brussels.

But for Charles Michel, Prime Minister of Belgium, Sunday's 20 kilometer de Bruxelles event has proven to be a little thorny. Michel says he has been suffering hearing loss since a starter pistol, signaling the beginning of the race, was fired near his left ear.

The moment was captured in a photo showing Princess Astrid of Belgium's royal family firing the gun into the air. Next to her is a wincing Michel, who appears to be recoiling at the sound.

The Prime Minister's spokesman, Barend Leyts, confirmed that Michel is suffering from an ear injury caused by the pistol's firing.

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