TEHRAN — The Iranian authorities hanged a man on Monday, three months after he was convicted in the deaths of three police officers who were run over and killed by a bus driver during a protest by followers of a mystical Sufi strain of Islam.

The man, Mohammad Salas, was accused of being the bus driver involved in the officers’ deaths during protests in February by Gonabadi Dervishes, a sect that the clerical government has designated a challenge to mainstream Shiite theology.

Mr. Salas’s trial before a revolutionary court, in March, was broadcast live on state television — with the feed cut during his defense — and his execution was taken as a message to potential dissidents challenging the authorities over rising prices.

Before the trial, the head of the Tehran Police had said that Mr. Salas was guilty of killing the three police officers and would be executed.