A tense standoff on an Ohio bridge turned violent as video captured a police officer repeatedly punching an anti-ICE protester during a protest that brought traffic to a halt.

The demonstration, which was on the Roebling Bridge between Cincinnati and Covington, called for the release of a detained former hospital chaplain. The protest drew some 100 people. Authorities say at least 15 people were arrested on felony rioting and various misdemeanor charges.

The viral video shows a protester wearing a red Cincinnati Reds cap being tackled and struck in the head multiple times while pinned to the ground. Police say the guy tried to grab a pepper ball gun from an officer, but he denies that claim, telling WCPO he was simply reacting to having a weapon pointed at him.

Covington Police Chief Brian Valenti said the officer who punched the guy feared he was reaching for a weapon and was attempting to prevent a fall into the Ohio River.