ST LOUIS (AFP) - The police arrested at least two people on Saturday as nightly protests in the racially troubled United States suburb of Ferguson over the police killing of unarmed black teenager Michael Brown shifted into the heart of St Louis.
Up to 50 youthful protesters gathered after sunset at the Midwestern city's historic 19th century court house, then marched through streets lined with bars packed with St Patrick's revellers before briefly halting traffic.
AFP reporters saw St Louis city police arrest two people - one a masked male protester dressed in black, the other news photographer Philip Montgomery, who was on assignment for the website Mashable.
Protesters have vowed to sustain their movement in the wake of a federal Justice Department probe into Brown's death on Aug 9 that prompted sometimes violent demonstrations as well as a fierce debate about policing and race relations in America today.
Five Ferguson residents have taken a first step toward ousting the city's Mayor James Knowles by delivering an affidavit last Friday to City Hall, the St Louis activist Organisation for Black Struggle said on its Twitter feed.
Mr Knowles, who met on Saturday with about 20 small-business owners at a Ferguson soul food restaurant, has declared he intends to stay in office, implement reforms and restore harmony in the city of 21,000 that is two-thirds African-American.
"We cannot describe how disgusted we are with you. We now ask that you vacate the office," wrote the five residents, whose names were not disclosed.
Their affidavit went on to urge Ferguson's six-member city council to call a special election to find a new mayor.
For the recall effort to succeed, signatures of 15 per cent of registered voters in the 2014 mayoral election - in which Mr Knowles won a second term by acclamation - would need to be collected within 60 days.
Five officials in Ferguson, including its police chief, have already resigned in the wake of a scathing US Justice Department report last week that exposed racial bias in the city's overwhelmingly white police department.
It described how police targeted African Americans in order to impose fines and generate revenue for the city - a practice that activists say is common in many American municipalities.
In a flurry of media interviews on Friday, Mr Knowles struck a defiant tone, saying he had no plans to resign at a time when civic leaders are trying to enact reforms and restore harmony to a divided and frustrated community.
"Right now, the community needs leadership," the mayor - a Ferguson native and Republican who is white and in his early 30s - told NBC News, adding that he enjoys "continued support from a lot of residents".
Speaking briefly to reporters on Saturday, Mr Knowles did not refer to the recall initiative. Instead he thanked local businesses for staying open despite big losses in turnover as consumers stay away.
"I appreciate that they stand with the city, and I stand with all of them," he said.
Ferguson has become a byword for racial tension since 18-year-old Brown was shot and killed by white police officer Darren Wilson on a residential street. His death ignited sometimes violent protests that spread across the country.
Tensions surged anew when shots rang out overnight on Wednesday amid an otherwise peaceful demonstration outside Ferguson police station, wounding two officers and prompting a manhunt that has stretched into the weekend.
St Louis County police chief Jon Belmar, now in charge of policing Ferguson's nightly protests, said detectives working "around the clock" were chasing several leads, but have yet to make an arrest.