Police hunt for suspects after officers shot in Ferguson

Police officers respond to a fellow officer hit by gunfire outside the Ferguson Police Headquarters in Ferguson, Missouri March 12, 2015. [Photo/Agencies]

Two Missouri congressman offered a $3,000 reward for information leading to an arrest.

In one video taken at the chaotic scene after the gunfire, a witness can be heard commenting, "Acknowledgement nine months ago would have kept that from happening."

The shooting came less than three months after a man ambushed two New York City patrolmen, seeking to avenge the killings of Brown and an unarmed black man in New York.

The White House sent a Tweet that read: "Violence against police is unacceptable," a message echoed by Brown's family. "We reject any kind of violence directed toward members of law enforcement," they said in a statement.

Investigators wasted no time in bringing people in for questioning but all of them were later released and no arrests were made, the St. Louis County Police said.

The shooter used a handgun and shell casings had been recovered, Belmar said.

Police and protesters appeared to disagree about where the shots originated. Belmar, who said police did not return fire, asserted the gunshots came from the middle of the crowd.

"I don't know who did the shooting ... but somehow they were embedded in that group of folks," Belmar said.

Protesters at the scene insisted the shots came from further away. "The shooter was not with the protesters. The shooter was atop the hill," activist DeRay McKesson said on Twitter.

Tom Jackson, the police chief, was the latest in a string of Ferguson officials who have quit after the Justice Department report. It found that the city used police to issue traffic citations to black residents to boost its coffers. The harassment created a "toxic environment."

The shooting reignited a months-long debate over the use of force by police against minority groups.