Protesters lobbed frozen bottles of water and chunks of concrete while police fired off pepper spray in small skirmishes that played out on the streets of Ferguson, Missouri, on Monday evening.
St. Louis County Police officials said safety had been compromised at the evening’s protests by crowds that began to pelt officers with debris. They then moved in to remove protesters from the city’s roadways.
The protests capped off a day of demonstrations across the St. Louis region marking the first anniversary of the death of 18-year-old Michael Brown at the hands of a Ferguson police officer.
Police said early Tuesday morning that they made 23 arrests as protests stretched into the wee hours of the fourth consecutive day.
On Monday afternoon, a group of about 200 protesters gathered outside a federal courthouse in downtown St. Louis and 57 people were arrested for blocking the entrance. Protesters later blocked a cross-country thoroughfare — Interstate 70 — during the evening rush hour and eventually regrouped in Ferguson at night.
Protesters who gathered along West Florissant Avenue on Monday night were told by officers with bullhorns to clear the roadway while others in riot gear forced people out of the street.
St. Louis County Police described on Twitter the warnings given to the crowd blocking traffic, noting commands to disperse had been given and that anyone who did not comply would be subject to arrest.
“Unruly crowd is throwing frozen water bottles at officers. Those who choose to act violent will be arrested,” the county police department announced on Twitter just after 10 p.m. CDT.
Monday marked the fourth consecutive night of protests. A demonstration in the same location Sunday was interrupted by a shootout between at least six individuals. Police also opened fire during the melee Sunday night, seriously wounding a man who officers said took shots at them.
As of 11 p.m. Monday, police said at least nine people had been arrested for interfering with an arrest or resisting police orders — including a woman whose was initially described by witnesses as a 12-year-old girl. An image of a short woman with her hands cuffed behind her back was circulated on Twitter, but county police quickly responded to say that the woman was actually 18.
St. Louis County Executive Steve Stenger declared a state of emergency Monday, authorizing St. Louis County Police Chief Jon Belmar to take control of police emergency management in and around Ferguson.
“They’re not going to take the street tonight. That’s not going to happen,” Chief Belmar told AP.
The chief was later seen walking among protesters and encouraging them to move to sidewalks “in an attempt to deescalate the situation,” police said. By 11:30 p.m. the protest had quieted down and the crowd appeared largely compliant with police orders.
• Jay LeBlanc contributed to this article, which is based in part on wire-service reports.