A new round of rallies was planned in and around Ferguson, Missouri, on Monday, hours after a man was critically wounded in a gun battle with police when peaceful protests to mark the fatal shooting a year ago of an unarmed black teenager by a white officer erupted into violence.
On Sunday night in the St. Louis suburb of Ferguson, several volleys of gunshots rang out as police in riot gear tried to disperse demonstrators blocking traffic and smashing storefront windows along a street that was a flashpoint of riots last year after 18-year-old Michael Brown was shot dead.
The death of Brown and a grand jury's decision to spare the officer, Darren Wilson, from criminal charges led to a wave of demonstrations that boiled over into rioting and arson at times and spawned sympathy rallies across the United States.
Brown's death also prompted greater scrutiny of racial bias within the U.S. criminal justice system, giving rise to the "Black Lives Matter" movement that gained momentum from other high-profile killings of unarmed minorities by white police in cities such as New York, Baltimore, Los Angeles, Cincinnati and most recently Arlington, Texas.
A day of civil disobedience was planned for Ferguson, parts of the St. Louis area and other major U.S. cities in rallies organizers said were aimed at bringing attention to police violence against racial minorities.
In Ferguson on Sunday night, police said the gunfire began with two groups of agitators apparently shooting at each other before one gunman darted across a parking lot and was confronted by four officers who pulled up in an unmarked vehicle.
The suspect then opened fire on the police vehicle and was badly wounded in the ensuing foot chase and exchange of gunshots with the four detectives, police said.
St. Louis County Police Chief Jon Belmar said the unidentified man, believed to be in his mid-20s, was hospitalized in critical and unstable condition.
Belmar said at a predawn news conference on Monday that police estimated that more than 40 rounds had been fired. The shooters "were criminals; they weren't protesters," he said. "There is a small group of people out there that are intent on making sure that we don't have peace that prevails."
U.S. Attorney General Loretta Lynch condemned the violence.
"As we have seen over the recent months and years, not only does violence obscure any message of peaceful protest, it places the community, as well as the officers who seek to protect it, in harm’s way," Lynch said in prepared remarks to the Fraternal Order of Police.
In March, the Justice Department released a report that said systemic racial bias targeted blacks and created a "toxic environment" in Ferguson.
A federal review of Brown's death found that Wilson had acted lawfully.
The U.S. Department of Justice, however, also found a pattern of excessive police force against unarmed black citizens. The city's police chief, city manager and municipal court judge subsequently left their jobs.
At least three officers were injured in Sunday's melee. One was struck in the face with a brick hurled from the crowd and two others pepper-sprayed by protesters, Belmar said.
A local news media member was also robbed and assaulted in a nearby parking lot amid the turmoil, during which police reported making five arrests.
Separately, two teenage males were shot early on Monday in a drive-by attack near a sidewalk shrine erected in Brown's memory beside the spot where he was killed, but their wounds were not considered life-threatening, police said.
The violence was in marked contrast to a day of mostly subdued, peaceful commemorations in Ferguson and elsewhere.