Police say protesters in Ferguson, Missouri, began hurling Molotov cocktails at them Sunday night, forcing them to respond with tear gas and rubber bullets.
The incident began when protesters started moving toward a police command center and refused to stop, CNN reports
. One man was had his hands in the air, but continued walking toward the command center, a CNN reporter on the scene said.
The crowd of about 400 appeared to be marching peacefully, but a spokesman for the Missouri Highway Patrol said "aggressors" had advanced on the command post.
"We ordered them back. We ordered them back again. After several attempts, we utilized the smoke to disperse these individuals," said Missouri Highway Patrol Corporal Justin Wheetley
Multiple protesters insisted they were marching to the command center with their hands up and that nobody threw Molotov cocktails or fire bombs.
Hundreds of protesters fled the police smoke and tear gas.
A CNN reporter on the scene said he saw at least one protester fire a shot. A reporter and a photographer for Reuters said they heard gunfire, but were note sure where it was coming from.
CNN contributor Marc Lamont Hill said police told him a "Code 2000" had been issued, meaning that all available law enforcement officers, regardless of their agency were needed.
Ferguson was the scene earlier in the day a church service memorializing Michael Brown Jr., the 18-year-old unarmed black man shot by white Police Officer Darren Wilson on Aug. 9.
Hill told CNN that the scene had been tense on Sunday even after the peaceful memorial service. He said an officer pointed a gun at him in a "very threatening manner" before he could get out of his parked media vehicle.
"I immediately screamed, 'I'm media, I'm media," Hill said. "So I think if kind of energy's in the air combined with some protesters who aren't doing the right thing, I think it creates a very, very, very dangerous mix."
CNN also reported that at least three journalists were briefly arrested by Capt. Ron Johnson of the Missouri State Troopers, who is now in charge of the police presence.
Democratic operative Donna Brazile urged protesters to remain peaceful.
The Rev. Jesse Jackson repeated the concern of others that the police had suited up in riot gear in advance of the action. He described the protests as calm up until the tear gas was fired by police.
"There was no sense in any of those groups that there was something violent on the horizon," Jackson told CNN.
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