DEVELOPING: "Multiple" police offers were shot Thursday night in Dallas — with reports that five officers may be in "grave condition" — during a protest over the recent fatal shootings of African Americans by police.  

Fox News affiliate KDFW-Fox4 reports that as many as six officers were shot, and that SWAT officers are negotiating with at least one of two suspects in the shooting, a man reportedly wearing what appeared to be a bullet-proof and tactical gear.

Fox4 cameras captured protesters running away from the scene of the shooting shortly before 9 p.m. local time. A cameraman approached the scene and captured officers apparently lying on the ground.

A Fox4 reporter said he heard approximately 10 gunshots downtown. That reporter was told by an officer police were searching for someone with a rifle.

The status of the shooter was not immediately clear. Aerial images showed officers appearing to focus their search on a parking garage.

Witness Carlos Harris told the Dallas Morning News the gunfire was "strategic. It was tap-tap-pause. Tap-tap-pause."

Michael Batista told KDFW the protest march had been "very peaceful" before the shooting started.

Brittany Peete, a demonstrator, told the Associated Press she didn't hear the gunshots, but she "saw people rushing back toward me saying there was an active shooter."

Peete said she saw a woman trip and nearly get trampled as people ran to get to safety.

"Everyone just started running," Devante Odom, 21, told The Dallas Morning News. "We lost touch with two of our friends just trying to get out of there."