Missouri Governor Jay Nixon has named an African-American state Highway Patrol captain to oversee security in Ferguson, after scathing criticism of the local police department's handling of protests over an officer's fatal shooting of a black teenager.
Highway Patrol Captain Ron Johnson, who grew up in the Ferguson area, said at a news conference on Thursday that he would emphasise respect for the entire community as he takes over operations.
"What's gone on here over the last few days is not what Missouri is about, it is not what Ferguson is about. This is a place where people work, go to school, raise their families and go to church, a diverse community, a Missouri community," Nixon said at a news conference in Ferguson, where he met police, prosecutors and members of the community.
"But lately it has looked a little bit more like a war zone, and that is unacceptable," he said.
Earlier, US President Barack Obama called on police to respect demonstrators in an attempt to defuse tensions in Ferguson after 18-year-old Michael Brown's death on Saturday set off demonstrations.
Lawmakers, activists and demonstrators have complained that the mostly white police force has escalated the violence by using military gear and tear gas.
Police have pledged to do better but have also justified the tactics, saying they have responded to the threat of violence during protests.
Nixon said local police would not be pulled out of Ferguson but that state troopers would direct the team.
"We are going to have a different approach," Johnson said at the news conference with Nixon. He said he would go to "ground zero" on Thursday evening, the area where Brown was killed and also where a convenience store was burned down on Sunday in riots.
Additionally, US Attorney General Eric Holder said in a statement that police had accepted an offer of technical assistance from the Justice Department "to help conduct crowd control and maintain public safety without relying on unnecessarily extreme displays of force".
There have been dozens of arrests over the last few days and complaints that police have come down too hard on protesters and on reporters covering the demonstrations.
Since Sunday, there have been peaceful vigils and demonstrations - with protesters holding their hands in the air and chanting "hands up, don't shoot" - as well as episodes of looting, vandalism and violence.
Nixon has been under pressure from Missouri lawmakers to step in and change tactics in Ferguson, which they said have only escalated tensions.
Protesters have also decried what they say is a lack of transparency by police investigating the incident - including the refusal to release the officer's name. And some have called for St Louis County Prosecuting Attorney Bob McCullough to be removed from the case.
Early on Thursday, a member of the Anonymous hacker activist collective, using the Twitter name @TheAnonMessage, tweeted a name, alleging it was the police officer who shot Brown.
Police and prosecutors strenuously denied that the person named was the officer involved, saying he was not even a member of the St Louis County Police Department or the Ferguson Police. Later, another collective member, tweeting as @OpFerguson, said the name was incorrect.
Hackers have periodically disrupted the Ferguson police website and other local government sites throughout the week.
The shooting and protests have shed a spotlight on race issues in the highly segregated city of St Louis and its suburbs.
Ferguson has seen a stark demographic shift in recent decades, going from mostly white to mostly black. About two-thirds of the town's population of 21,000 is black. Still, on a police force of 53, just three officers are black.
Civil rights groups have complained in the past that police in St Louis County racially profiled blacks, arrested a disproportionate number of blacks and had racist hiring practices.
Amnesty International called on Thursday for a thorough investigation of the shooting of Brown, as well as the tactics used against protesters.
The US Department of Justice, the FBI and the St. Louis County prosecutor's office are all investigating Brown's death.
There is little clarity on what occurred during Saturday's incident.
Police have said that Brown struggled with the officer who shot and killed him. The officer involved in the shooting was injured during the incident and was treated in hospital for swelling on the side of his face, they said.
But some witnesses have said that Brown held up his hands and was surrendering when he was shot multiple times in the head and chest.
PRESIDENT APPEALS FOR CALM
Obama is appealing for "peace and calm" on the streets of the St Louis suburb.
"I know emotions are raw right now in Ferguson and there are certainly passionate differences about what has happened," Obama said in his first in-person remarks about the tense standoff.
"But let's remember that we're all part of one American family, we are united in common values and that includes the belief in equality under the law, respect for public order and the right to peaceful public protests."
Obama, speaking from the Massachusetts island where he's on a two-week vacation, said there was no excuse for excessive force by police in the aftermath of Saturday's shooting of Brown. He said he had asked the Justice Department and FBI to investigate the incident.
"There is never an excuse for violence against police or for those who would use this tragedy as a cover for vandalism or looting," Obama said in televised remarks.
"There's also no excuse for police to use excessive force against peaceful protesters or to throw protesters in jail for lawfully exercising their First Amendment rights," he told the media from Edgartown, Massachusetts, near where he is vacationing with his family.
The president said he had also spoken with Nixon, who has faced criticism for not doing more to control the violence. Obama defended the Democratic governor calling him "a good man, a fine governor".
Police have defended their use of tear gas and smoke bombs to repel protesters, saying they took those actions to disperse a large crowd after some people threw Molotov cocktails and rocks at officers.
- Reuters and AP