US Attorney General Eric Holder has termed the attack on two police officers in the city of Ferguson as "inexcusable" and "cowardly" and warned that it would endanger reforms in policing.
"Such senseless acts of violence threaten the very reforms that nonviolent protesters in Ferguson and around the country have been working towards for the past several months," said Holder in a statement, according to a Xinhua report.
"This heinous assault on two brave law enforcement officers was inexcusable and repugnant," he stated.
Two police officers were shot and wounded during a protest against the Ferguson Police Department, which has been under fire since one of its officers, Darren Wilson, shot and killed an unarmed black teenager Michael Brown in August last year.
"These police officers were standing there and they were shot, just because they were police officers," St. Louis County Police Chief Jon Belmar said.
On Wednesday, Ferguson police chief Tom Jackson resigned, after a federal report pointed out a culture of racism within the police department and municipal offices in the city.
More From This Section
Protesters in Ferguson gathered around the police headquarters on Wednesday after Ferguson police chief Thomas Jackson announced that he would resign.
Ferguson, a city in the US state of Missouri and the county of St. Louis, has seen heightened tensions following Brown's shooting. A number of black men were killed in the US by the police last year, which resulted in a wave of protests.
Belmar said the police did not have any suspects yet, but that they had some possible leads that the investigators were exploring.
Following the attack on the police, officials said on Thursday that St. Louis County Police and the Missouri State Highway Patrol would take over security responsibilities related to the protests in Ferguson.
In an investigation report about the policing practice in Ferguson, released on March 4, the US Department of Justice concluded that a widespread pattern of racial bias existed within the Ferguson Police Department and other local law enforcement agencies.
The report worsened the resentment against the Ferguson police.
Holder had said that the justice department would use all its authority to ensure reforms in law enforcement agencies in Ferguson, including drastic measures such as dismantling the Ferguson Police Department.