More than 20 people have been arrested in Ferguson, Missouri, amid protests marking the anniversary of the death of unarmed black teenager, Michael Brown.
A state of emergency was declared, as officers in riot gear forced people off the streets on Monday night.
A police spokesman said 23 people were detained, but “there were no shots fired, no smoke or tear gas used”.
About 200 demonstrators, some waving flags, beating drums, and shouting anti-police slogans, marched along a street that was a flashpoint of riots that erupted last year after white police officer, Darren Wilson killed 18 year old Michael Brown.
Police carrying shields rushed into a crowd of protesters around midnight, prompting many to scream and run away.
Twenty-three people were arrested, some for throwing frozen water bottles and rocks at officers, according to the St. Louis County Police Department.
Monday’s demonstrations capped a day of civil disobedience called by activists to protest against the shooting of Brown and other unarmed black men by police across the United States.
Clergy and civil rights groups led a series of protests, staging a demonstration at a courthouse in St. Louis where 60 people were arrested, including Princeton University professor and activist, Cornell West, according to a protest organizer.
Police arrested several dozen other protesters who blocked rush-hour traffic on Interstate 70 a few miles from Ferguson hours later, according to a Reuters witness.
The death of Brown and a grand jury’s decision to spare the white officer from criminal charges provoked a wave of demonstrations that boiled over into rioting and arson at times and spawned sympathy rallies across the country.
On Sunday, Tyrone Harris, was critically wounded after being fired on by police in Ferguson.
The authorities said that Mr Harris was armed and opened fire, but his father had described their account of events as “a bunch of lies”.
Prosecutors have filed 10 charges against him, including assaulting an officer.
The shooting followed a day of peaceful and sombre commemorations in memory of Michael Brown.
The 18 year old was shot in August 2014 by a white police officer who was later cleared of any wrongdoing by a grand jury and the US Department of Justice.
The death triggered a wave of protests over alleged racism and the use of excessive force by US police officers.
