By USA Today: Greg Toppo and Melanie Eversley, USA TODAY

Multiple snipers shot 11 police officers from a building during a protest against police brutality, killing five, Dallas Police said Thursday night.

Dallas Police Chief David O. Brown earlier said two officers were in surgery and three were in critical condition.

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Brown initially said 10 officers were shot, but a short time later said an 11th officer had been shot in an exchange of gunfire with one of the suspects. The officers include Dallas Police and Dallas Area Rapid Transit officers. Those shot were taken to Parkland Memorial Hospital and Baylor University Medical Center.

Talking to reporters late Thursday, Brown said police were circulating a photo of a "person of interest" in the case who appeared to be openly carrying a rifle during the march. That person turned himself in, according to a later tweet by the department.

Another person was taken into custody after a shootout. The bomb squad was checking out a suspicious package discovered after the shootout, police said.

Brown said Dallas police had contacted the FBI and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives “to help us search for both these suspects — or maybe it’s more — and to do a very thorough search of this area where we believe there might be a bomb planted.”

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Dallas Area Rapid Transit tweeted that four of its officers were among those shot and that one of them had died. The three others had non-life-threatening injuries.

One police officer was taken to Parkland Memorial Hospital, the same hospital wherePresident John F. Kennedy was pronounced dead after being shot Nov. 22, 1963, WFAA reported. A hospital representative referred questions to Dallas Police.

Live video feeds from news organizations and reports from witnesses painted a picture of a chaotic scene, with police cars converging on a downtown building.

Marchers protesting police shootings were moving down Lamar Street near Griffin when shots were fired.

One witness told The Dallas Morning News that he heard "what sounded like six to eight shots."

A bystander who was at the scene told WFAA the shooter stood by as the rally passed him, then opened fire on officers.

Another bystander, Richard Adams, said the protest was "a lovely, peaceful march," until they were walking down Commerce Street near the Bank of America building parking garage when he heard what sounded like "a bunch of firecrackers going off."

"Everybody just stopped — 'Run, run for your lives!' Women with children and babies and everybody was chaotically running. And then, maybe I was a half-a-block away, calming down a little bit when we heard it again. [...] There must have been five times tonight — whenever we thought we were safe, people said 'Run, people were shot!'"

According to the Dallas police scanner, officers were looking for a light-skinned black male armed with AR-15 type rifle. He was described as wearing black shorts and a camouflage shirt. Dallas Police tweeted a photo of the suspect, asking for the public's help in locating him.

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Before shots rang out, the Dallas Police Department was live-tweeting the protest, even posting photos of officers posing with demonstrators.

The shooting took place near El Centro College. Friday classes have been canceled.