Forty-nine people, including prominent US activist and author Cornel West, have been arrested in Ferguson, Missouri, following a "weekend of resistance" over the killing of an unarmed black teenager in August.
West was released later, while there was no confirmation if the others remained in police detention.
Hundreds of people, including religious leaders, hit the streets, taking part in protests and several acts of civil disobedience, on what was being dubbed as "Moral Monday".
A few of the protesters tried to block a door of the police headquarters leading to a face-off with law enforcement officers wearing riot gear.
Forty-three people were arrested outside the Ferguson police department during the demonstrations over the shooting of Michael Brown by Darren Wilson, a white police officer.
Activists from across the country had come to join the four-day protests branded as "Ferguson October" to draw attention to the alleged police mistreatment of black people.
"The weekend has been incredible to help re-energise those of us that are here," Ferguson Democratic Committeewoman Patricia Bynes told the Reuters news agency.
Several local and national religious leaders have also been taking part in the protests hoping to build momentum for a nationwide movement against police violence.
"The faith community is standing shoulder to shoulder with the people of Ferguson in one of the defining civil rights moments of our generation," Reverend Deth Im, member of the PICO National Network group of faith-based community organisations, said in a statement issued on Monday.
A grand jury is currently considering charges against Wilson, who has been placed on administrative leave.
Protesters want Wilson arrested immediately and have called for the appointment of a special prosecutor.
The US Justice Department has launched a civil rights investigation into Brown's death.