Two officers have been shot outside the police department in Ferguson, Missouri, according to reports.
It comes after the chief of the Ferguson police department resigned following a scathing government report that exposed racial biases.
Chief Thomas Jackson’s resignation will become effective on 19 March, the city said in a statement on Wednesday.
He is the latest Ferguson city official to resign in the wake of the US Department of Justice report that highlighted systemic racially biased practices by the police and municipal court.
The Ferguson City Council voted unanimously on Tuesday to accept the resignation of City Manager John Shaw, who oversaw the police department.
That followed Municipal Court Judge Ronald Brockmeyer’s decision to step down on Monday.
The St Louis suburb has been hit by unrest since a white police officer fatally shot 18-year-old Michael Brown last summer.
Last week, the Justice Department said in its findings that Ferguson’s police and court systems operated as a money-making enterprise which heightened tensions among residents.
Mr Jackson, who had previously resisted calls from protesters and some of Missouri’s top officials to resign, told the St Louis Post-Dispatch he felt it was time for him to move on.
“I believe this is the appropriate thing to do at this time,” he said. “This city needs to move forward without any distractions.”
The 57-year-old embattled chief was widely criticised for his handling of the 9 August shooting of Mr Brown and subsequent protests.
In his resignation letter, obtained by the Post-Dispatch, Mr Jackson said: “It has been an honor and a privilege to serve this great city and to serve with all of you.
“I will continue to assist the city in anyway I can in my capacity as private citizen.”
Ferguson Mayor James Knowles denied rumours that he would also resign, the newpaper reported on Wednesday.
The city plans to launch a nationwide search for a new police chief, it said in a statement.
Meanwhile, Mr Brown’s family have said they will file a civil wrongful death lawsuit against Ferguson and Darren Wilson, the former officer who shot dead the unarmed teenager.
Mr Wilson, who said he acted in self-defence, was cleared by a grand jury and the Justice Department of any wrongdoing.