A young man has been shot during a late-night confrontation between riot police and protesters in Ferguson, Missouri, according to police.
St Louis Country Police said earlier reports that two people had been shot during Sunday's incident were not correct, however a second person, a member of the local media, was assaulted and robbed near the scene.
The incident came after a day of peaceful events commemorating the fatal shooting of an unarmed black teenager by a white officer one year ago.
Police said gunshots erupted as police were seeking to disperse a crowd of protesters who began blocking traffic and smashing windows along a street that was a flashpoint of last year's unrest following the slaying of 18-year-old Michael Brown, according to their statement.
They allege that Tyrone Harris had exchanged gunfire with another suspect. The police say that Harris, 18, was shot as police pursued him, after he began firing at them.
Harris was transported to hospital where he is in a critical condition.
He was later charged with offences including assaulting police and shooting a motor vehicle.
However, Harris' father told the Associated Press the police version of events was "a bunch of lies".
Tyrone Harris Sr said his son was unarmed and and had been drawn into a dispute involving two groups of young people.
"My son was running to the police to ask for help, and he was shot," he said. "It's all a bunch of lies ... They're making my son look like a criminal."
The St Louis County Police Department tweeted that "multiple shots" had been fired.
An AFP journalist heard about two dozen shots ring out and saw one bloodied protester lying on the ground.
Protesters who had gathered in the street fled in multiple directions, hiding behind cars and taking cover in buildings, the AP news agency said.
Source: Al Jazeera and agencies