An anti-mask rally outside a California cancer treatment center turned violent on Thursday, with a patient who confronted the protesters saying she was sprayed with bear mace and punched repeatedly in her surgery scars.

The incident occurred outside the Cedars-Sinai Breast Health Services building in Hollywood, where dozens of anti-maskers with signs and a megaphone gathered to protest the clinic's mask requirement, harassing doctors and patients. Kate Burns, a breast-cancer patient, approached the protesters and asked them to leave, according to video posted online.

"I get treated here, get the f*ck away," Burns said. When one of the protesters asked why she was angry, Burns responded "Because I've just gone through f*cking breast cancer, and you motherf*ckers are here."

When one of the anti-maskers told Burns the protest had "nothing to do with" her, she responded: "You are protesting a breast cancer f*cking center. It has everything to do with me and my community. Do you know anything about chemotherapy? Do you know what happens to the immune system?"

Protesters then asked Burns if she was familiar with the Civil Rights Act. "Get on the right side of history. You've got a lot of anger you need to release. It's a very dangerous emotion," one man told her. After more anti-maskers and some anti-fascist counterprotesters arrived, the scene turned violent. Video shows Burns getting punched and shoved by a woman with a megaphone.