Ferguson, Missouri (CNN)[Breaking news updates, published at 3: 54 am]
From St. Louis County Police Chief Jon Belmar: There were two shootings Sunday night. One of the shooter engaged in gunfire with officers and was shot. He was in critical condition, undergoing surgery. He had on him a stolen 9mm.
The four plainclothes officers who were involved in the shooting have between six to 12 years of experience, he said. They have been placed on administrative leave. Asked about the officers' race, Belmar said "I am not going to comment."
There were two shootings Sunday night. One of the shooters engaged in gunfire with officers and was shot, he said. He was in critical condition, undergoing surgery. He had on him a stolen 9mm, according to Belmar.
Belmar asked anyone with video of the Sunday night shooting to share with the department. "We cannot continue, we cannot talk about the good things that we have been talking about, if we are prevented form moving forward with this kind of violence."
One officer was treated for a laceration after taking a brick to the face, Belmar said.
Police used smoke bombs to disperse crowds, not tear gas canisters, Belmar said. The department also denied that it used rubber bullets. "The department does not use rubber bullets, and we never have used rubber bullets," the department told CNN.
[Latest story, published at 3:16 am]
A day of peaceful vigils to mark the one-year anniversary of Michael Brown's shooting death turned chaotic late Sunday night when gunfire sent protesters running for cover and prompted police reinforcements.
In one of at least two incidents, police were involved in a shooting after they came under "heavy gunfire," said St. Louis County Police spokesman Shawn McGuire.
No officers were injured, the department said. It said it will release more details later. But word circulated, along with a video, that the person shot was another black man, ratcheting up the tension.
"We're ready for what? We're ready for war," crowds chanted.
Some of the shots rang out as reporters were talking to Ferguson's acting police chief, Andre Anderson. A startled Anderson continued speaking with a steady burst of gunfire in the background. Crowds scattered.
Elsewhere, several objects were thrown at police and some businesses damaged, the St. Louis County Police Department said. At least two unmarked police cars had bullet holes on them.
Authorities said they were trying to restore order. Police, with helmets and shields, pushed crowds back and called in tactical units. Some residents held on to their children and watched.
"Multiple shots fired in Ferguson," the St. Louis Police Department tweeted. "Please leave the area of Ferguson and West Florissant."
West Florissant Avenue is where Brown was shot.
The details of what happened on August 9, 2014, and the days of protest that followed have become a polarizing topic in Ferguson and America as a whole.
Brown's killing by officer Darren Wilson sparked outrage and protests nationwide against what some described as racial bias by the police.
Brown was an unarmed black teen; the officer was white. A grand jury didn't indict Wilson and the Justice Department also declined to bring criminal charges.
The killing sparked weeks of protests that at times intensified into street fires and looting of businesses. Police fired tear gas in response, sparking more tensions.
Wilson retired from the Ferguson Police Department.
But protesters — many of whom are skeptical of the local and federal inquiries into the case — point to the concrete examples of police misconduct exposed in the wake of Brown's death. The case also led to new policing strategies, including police body cameras that have injected truth into areas where there was once only debate.
'Pray for peace'
Amid the chaos early Monday, some appealed for calm.
"Please pray for peace in Ferguson tonight and forever," Danny Takhar tweeted. "And the police department really needs to look at what they did last year and today."
Others posted a video of what they described as a victim of the shooting in Ferguson, lying on the streets bleeding.
"Please get him some help! He's bleeding out," a voice said off-camera.
Overnight Saturday, a teenager was arrested and charged with two counts of unlawful use of a weapon and one count of resisting arrest, the St. Louis County Police said in a statement. The victim, 22, was transported to hospital with nonlife-threatening wounds.
But throughout the day Sunday, peaceful vigils marked Brown's death. Attendants observed four and half minutes of silence. Brown's body lay on the street for four and a half hours after he was shot.
Events highlighting what's described as a day of civil disobedience are planned for Monday. In the past, such events have included blocking highways and shutting down big businesses across St. Louis County.
As Sunday night gave way to Monday, police and protesters faced off in a tense standoff on West Florissant Avenue,
Then came the shooting.