Protesters gathered near the Ferguson, Missouri, police headquarters and chanted slogans like "the whole damn system is guilty as hell" in what appeared to be a peaceful demonstration one night after two police officers were shot.
Demonstrators briefly blocked a road during the protest on Thursday night. About 100 protesters and 20 police officers were visible, NBC affiliate KSDK reported.
Earlier, religious leaders and demonstrators held a candlelight vigil and prayed not only for the wounded officers and their families but for protesters and the nation.
"Whoever was the culprit last night did not come from this community," Rev. Traci Blackmon said, noting that no police officers were shot during months of protests, even when anger over the fatal police shooting of Michael Brown was at its height. "We will not be moved. We will not give up."
St. Louis County police and the state Highway Patrol took command of protest security.
The night earlier, just after midnight, a St. Louis County police officer was shot in the shoulder and an officer from the St. Louis suburb of Webster Groves was shot in the face outside Ferguson police headquarters as a protest wound down, police said.
Investigators took several people in for questioning. They were released, and no arrests were made, said Sgt. Brian Schellman, a spokesman for St. Louis County police. St. Louis Regional Crimestoppers offered a $10,000 reward for information leading to the arrest of the shooter or shooters.
Both officers were released from the hospital Thursday. St. Louis County Police Chief Jon Belmar said three or four shots were fired at a group of police from about 125 yards away. He called the shootings an "ambush" and said the officers were lucky to be alive.
The shootings were condemned by the parents of Michael Brown, whose death at the hands of a Ferguson police officer in August touched off civil unrest. They called the shootings "senseless" and blasted "stand-alone agitators" attempting to derail peaceful protests.
Attorney General Eric Holder called the shootings a "disgusting and cowardly attack" carried out by "a damn punk." President Barack Obama also condemned the violence, and said on Twitter that the "path to justice is one all of us must travel together."
Ferguson Mayor James Knowles III called for calm. "While we respect the right to peacefully protest, we cannot continue to move forward under threats of violence and destruction to our community," the city said in a statement Thursday.
Several Ferguson officials, including the police chief, Thomas Jackson, have resigned after a Justice Department report found a pattern of racial discrimination in the city's police and court systems.
While county police and the Highway Patrol will be provide security, regular policing will continue to be conducted by the Ferguson police, authorities said.
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