On Wednesday, the Minuteman Project protested San Francisco's sanctuary policy and their mayor Gavin Newsom. According to MMP leader Jim Gilchrist, one of the counterprotesters tried to throw a "chemical bomb" in a glass vial at him. It bounced off Gilchrist's assistant Tim Bueller, hit the ground, and made a loud noise as it detonated. Apparently no one was injured. The police arrested the person who threw the "bomb". There's a text blurb here, and audio where Gilchrist discusses this is here.