A police officer in Brazil was suspended on Friday pending an investigation after he was caught on video firing a rubber bullet at a protester who had accidentally knocked his cap off.

The incident took place during a protest march Thursday night in the northeastern city of Recife, where local activists from the Occupy Estelita movement are trying to block a private real estate development project at the José Estelita Pier in the city’s historic center. The protesters want the space to be a public park.

The images show that protesters carrying a large banner across a road raised it as they passed an officer, glancing against his head and knocking off his cap. Seconds later, he calmly raised his rifle and fired a blast at one of the protesters only steps away.