A group of anti-Trump protesters laying in the middle of a San Francisco street for a “die-in” Wednesday got a rude awakening when a man on a red motorcycle drove through the demonstration.

A video of the incident showed the motorcyclist revving his engine and slowly driving through the demonstrators, causing mass panic.

Police asked the biker to stop before he could drive through the wall of people a second time. When the driver did not heed the officers’ calls to stop, one of the officers pulled out a gun and then arrested him, CBS San Francisco reported.

Police say the charges are not determined yet and have not released the biker’s identity.

“He was definitely targeting us,” protest organizer Emily Lee said. “It was unclear if it was for political reasons or if he was just mentally unstable or what, but it was terrifying.”

Nobody was injured in the incident, police say.

The “die-in” in San Francisco was just one of a series of protests put on by anti-Trump protesters who oppose the Republican health care legislation known as the American Health Care Act that is moving through the Senate.

On Capitol Hill in Washington, D.C., protesters also conducted a “die-in” outside Senate Majority Leader Mitch McConnell’s office Thursday. Many protesters were dragged out of the building for blocking the hallway to the office.