O'FALLON, Mo. (AP) — Missouri protests continued Monday over the death of George Floyd and police treatment of African Americans, with gatherings in Kansas City, Jefferson City and St. Louis, where protesters smashed windows on a downtown business and stole items before the building caught on fire.

Monday's protests came after peaceful daytime protests Sunday led to spurts of chaos overnight into Monday, with vehicles and buildings damaged and officers firing tear gas after being pelted with rocks, fireworks and Molotov cocktails. The nationwide protests were sparked by the May 25 death of Floyd, a handcuffed black man who pleaded for air as a white Minneapolis police officer pressed his knee against Floyd’s neck until he stopped breathing.

On Monday afternoon, several hundred people rallied peacefully outside the justice center in downtown St. Louis, including Mayor Lyda Krewson and St. Louis Public Safety Director Jimmie Edwards. Protestors later walked to the Gateway Arch National Park and then onto nearby Interstate 64. But later Monday, protesters gathered in front of police headquarters, where officers fired tear gas. Some protesters smashed windows at a downtown 7-11 store and stole items from inside before the building was set on fire.

On Monday afternoon, Kansas City Mayor Quinton Lucas and Police Chief Rick Smith kneeled with protesters gathered at the Country Club Plaza entertainment district and had what police spokesman Sgt. Jake Becchina later described as a good conversation with the crowd.

Not long after, Becchina said items were thrown at police and pepper spray was used. More people began to arrive later in the evening and he said about “half a dozen”people had been detained, some who had sacks of rocks and bags of urine.

Nearly 2,000 protesters gathered early Monday evening on the Capitol grounds in Jefferson City, carrying signs reading “white silence is violence” and “say their names.”

Police estimated that more than 1,500 people turned out in O'Fallon, about 35 miles (56.33 kilometers) west of St. Louis. The St. Louis Post-Dispatch reported that Police Chief Tim Clothier locked arms and marched with protesters, saying he wanted to show support for their cause.

"We do not agree with what happened. We do not want to condone the behavior of that one officer,” Clothier said.

Republican Gov. Mike Parson said Monday that the Missouri National Guard and the Missouri State Highway Patrol are ready if violence persists.

“We support peaceful protesters and we are committed to protecting the lawful exercise of these rights,” Parson, a former sheriff, said. “But violence and destruction will never be the answer. It does not help us achieve justice or peace. Instead it terrorizes innocent people and families, destroys our communities and creates more anger and pain.”

The protests came after tensions boiled over Sunday in Kansas City and Ferguson, the city in St. Louis County that became synonymous with the Black Lives Matter movement after the August 2014 killing of Michael Brown, a black 18-year-old, by a white police officer.

Just as in 2014, the Ferguson Police Department was a focus of demonstrators on Sunday for a second night. Police began dispersing the crowd shortly after 10 p.m., but some people damaged windows at Ferguson Brewing Co. just down the street. Minutes later, after someone threw a Molotov cocktail at a police car, officers responded with tear gas and ordered protesters to clear the area.

St. Louis County police reported that two officers suffered minor injuries. One was hit by fireworks, the other by a rock. Six people were arrested, police spokesman Benjamin Granda said.

Missouri Attorney General Eric Schmitt said Marcus Marvin Hunt was arrested Saturday in St. Louis and accused of distributing information on making explosives and destructive devices. Schmitt said a person in St. Louis was charged with organizing and promoting a riot. The second suspect's name wasn't released.

Sunday’s protest in Kansas City wasn’t as violent as Saturday’s, when 85 people were arrested and several businesses were damaged. The Sunday gathering of more than 1,000 people near the Country Club Plaza was peaceful enough that police waived an 8 p.m. curfew.

But later Sunday night, police used tear gas to break up the protest that included damage to businesses and fire that destroyed a KSHB-TV news vehicle. Police fired tear gas into the crowd after objects were thrown at them.

Sixty-three people were arrested Sunday, but only after protesters began pelting officers and were warned to leave, Smith said.

“At that point, when we started getting bottles hurled and rocks hurled, that’s when we used our chemical munitions to try and change the dynamics of the crowd and to get officers to not get assaulted while they’re standing there on the line,” Smith said Monday.

Including five protest-related arrests on Friday, 151 people were arrested in Kansas City over the weekend. Nearly two dozen officers were hurt by thrown objects, including two who were hospitalized.

The protests came amid otherwise violent weekends in both metropolitan areas. In Kansas City, two people died in separate shootings Sunday night, including one just blocks away from the protest site. In St. Louis, two people were killed and 17 people were injured in weekend shootings.