MADISON, Wis. (AP) — Fifteen people were arrested after a second night of violence erupted in Madison, with police firing tear gas as protesters again threw rocks and damaged store downtown stores following an earlier peaceful protest over the death of George Floyd.

There were also Sunday night protests in Milwaukee and Racine, continuing a weekend of unrest both in Wisconsin and across the country in reaction to Floyd’s death.

Madison police reported Monday that multiple stores were broken into in the State Street area, a business corridor that connects the state Capitol to the University of Wisconsin campus. On Saturday night, about 75 businesses were damaged. Police said multiple fires were set and several officers were injured by rocks and other projectiles that were thrown at them.

While the center of the violence was downtown, police said they also responded to reports of businesses being broken into across the city.

One of the 15 people arrested was armed with a handgun, police said. There were multiple unsuccessful attempts to steal a police squad car, the police said. On Saturday night, a police car was stolen and set ablaze. A protest Sunday night in Milwaukee was mostly peaceful, but a crowd that gathered outside of a city police station was dispersed with tear gas.

National Guard troops were deployed in both Madison and Milwaukee to assist local law enforcement. Both cities were operating under curfews designed to reduce the number of people on the street.

Madison police said there were several hundred people in the crowd Sunday night. A peaceful protest on Saturday drew more than 1,000 people, before a group of about 150 later that night turned violent.

In Racine, about 150 people marched to the police station where they threw rocks at police who were wearing riot gear. The crowd dispersed after police fired tear gas.

Floyd, who was black and handcuffed, died May 25 after a white Minneapolis police officer used his knee to pin Floyd to the ground for several minutes while Floyd pleaded for air and eventually stopped moving. The officer was charged with third-degree murder and manslaughter on Friday. He and the other three officers who were arresting Floyd were fired on Tuesday. None of the other officers have been charged.