Authorities on Wednesday disbanded what had been a command centre in Ferguson, Mo., for law enforcement responding to sometimes violent protests over the killing of black teenager Michael Brown by a white police officer.

Officers loaded up the remaining fire trucks and police vans that were part of the temporary law enforcement headquarters in a strip mall parking lot, rolling out after several days of subdued demonstrations.

Missouri Highway Patrol Captain Ron Johnson, who has led the response, told a news conference the Highway Patrol and St. Louis County police officers would continue to patrol, but the force had been substantially reduced.

"People are communicating with each other and it is already leading to change, not just in Ferguson but across our whole region," Johnson said.

Boarded-up stores were the only sign of the turmoil along West Florissant Avenue in Ferguson, which had been the site of clashes between demonstrators and police that led to scores of arrests after the shooting of Brown, 18, on Aug. 9.

A group of men and women from the St. Louis Youth Build organization handed out flyers on Wednesday in the apartment complex where Brown had lived, trying to recruit youths for construction and carpentry apprenticeships.

"Now people are standing up about something that happens all the time," Jermaine Brown, 40, who works for Youth Build, said of the unrest.

Johnson declined to discuss when state troopers would cede authority in the West Florissant corridor to local police.

Brown's death focused global attention on the state of race relations in the United States and evoked memories of other racially charged cases, including the fatal shooting of Trayvon Martin, a 17-year-old African-American, in Florida in 2012.

Demonstrators have demanded the arrest of officer Darren Wilson, who shot Brown, and seek changes in Ferguson where the majority of residents are black and most elected officials and police are white.

Wilson has been put on paid leave and is in hiding. His supporters have raised about $414,000 US for potential legal fees, relocation and living expenses, fundraising administrators said.

New appointment to Missouri agency

On the other side, $280,000 has been raised for Brown's family.

A St. Louis County grand jury has begun hearing evidence about the shooting and the U.S. Justice Department has opened its own investigation.

Police have said Brown struggled with Wilson, who shot and killed him. But some witnesses say Brown held up his hands and was surrendering when he was shot multiple times in the head and chest.

The National Guard was deployed to deal with the clashes between protesters and police, with Missouri Gov. Jay Nixon ordering them to withdraw from Ferguson on Aug. 21, a day after U.S. Attorney General Eric Holder visited the area.

Nixon on Wednesday appointed a new state public safety director, giving his administration its only black Cabinet member.

The governor said former St. Louis police chief Daniel Isom II will take over as director of the Missouri Department of Public Safety on Sept. 1. He will replace Jerry Lee, who resigned after almost three years as director.

The appointment comes after Nixon faced criticism both for the lack of racial diversity among his department leaders and for the state's response to protesters and looters following the Brown shooting.

The public safety director oversees both the patrol and the guard. He also oversees the state's emergency management agency.

With files from The Associated Press