FERGUSON, Mo. (AP) — A suspect who authorities say opened fire on officers in Ferguson, Missouri, on the anniversary of Michael Brown's death was critically wounded when the officers shot back, St. Louis County's police chief said Monday.

But the father of the suspect, 18-year-old Tyrone Harris Jr., called the police version of events "a bunch of lies." He said his son was unarmed and had been drawn into a dispute involving two groups of young people.

It was not immediately clear if the latest police shooting of a black suspect would spur renewed unrest in Ferguson, the site of many protests — some violent — in the aftermath of Brown's death on Aug. 9, 2014. Protest groups were quick to criticize the police response to protesters who gathered late Sunday along West Florissant Avenue.

St. Louis County Police Chief Jon Belmar said at a news conference that officers had been tracking the suspect, who they believed was armed, during a protest marking the death of Brown, the black, unarmed 18-year-old whose killing by a white Ferguson police officer touched off the national "Black Lives Matter" movement.

At the height of what was already a rowdy protest in which rocks and bottles were thrown at officers, gunshots rang out from the area near a strip of stores, including some that had been looted. Belmar believes the shots came from about six different shooters. It was not clear what prompted the exchange, but Belmar said the groups had been feuding.

At one point, the suspect crossed the street and apparently spotted the plainclothes officers arriving in an unmarked van with distinctive red and blue police lights, Belmar said. He said the suspect shot into the hood and windshield.

The officers fired back at him from inside the vehicle and then pursued him on foot when he ran.

The suspect fired on officers again after he became trapped in a fenced-in area, the chief said, and all four officers fired back. He was struck and fell.

The suspect was taken to a hospital, where Belmar said he was in "critical, unstable" condition.

Tyrone Harris Sr. told The Associated Press his son was a close friend of Michael Brown and was in Ferguson Sunday night to pay respects.

Harris said his son got caught up in a dispute among two groups of young people and was "running for his life" after gunfire broke out. He said his son had no weapons.

"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 father said he spoke with two girls who were with his son.

The suspect had a semi-automatic 9 mm gun that was stolen last year from Cape Girardeau, Missouri, Belmar said.

None of the officers was seriously injured. All four have been put on administrative leave, which is standard procedure. They were not wearing body cameras, Belmar said.

The shooting happened around 11:15 p.m. Sunday, sending protesters and reporters running for cover.

Belmar waved off any notion that the people with the weapons were part of the protest.

"They were criminals. They weren't protesters," he said.

Some protest groups were critical of police.

"It was a poor decision to use plainclothes officers in a protest setting because it made it difficult for people to identify police officers, which is essential to the safety of community members," Kayla Reed, a field organizer with the Organization of Black Struggle, said in a statement.

"After a year of protest and conversation around police accountability, having plainclothes officers without body cameras and proper identification in the protest setting leaves us with only the officer's account of the incident, which is clearly problematic."

Early Monday, another reported shooting drew officers to an apartment building in the area. Two males told police they were targeted in a drive-by shooting near the memorial to Brown outside Canfield Apartments. A 17-year-old was shot in the chest and shoulder while a 19-year-old was shot in the chest, but their injuries were not life-threatening, the St. Louis County Police said in a news release.

Separately, police said a 17-year-old suspect has been charged with unlawful use of a weapon and one count of resisting arrest after he fired shots near the protesters late Sunday. He is being held on $100,000 bond.

The anniversary of Brown's killing, which cast greater scrutiny on how police interact with black communities, has sparked days of renewed protests, though until Sunday they had been peaceful and without any arrests.

Before the gunfire, protesters were blocking traffic and confronting police. One person threw a glass bottle at officers but missed.

For the first time in three consecutive nights of demonstrations, some officers were dressed in riot gear, including bulletproof vests and helmets with shields. Police at one point early Monday shot smoke to disperse the crowd that lingered on West Florissant, Belmar said.

One officer was treated for cuts after a rock was thrown at his face, and two officers were pepper-sprayed by protesters, county police said. Five people were arrested.

Several other peaceful events earlier Sunday were held to mark the anniversary. Brown's father, Michael Brown Sr., led a march that started at the site where Brown was fatally shot by officer Darren Wilson. A grand jury and the U.S. Department of Justice declined to prosecute Wilson, who resigned in November.

Later, a few hundred people turned out at Greater St. Mark Family Church for a service to remember Brown.

Organizers of some of the weekend activities pledged a day of civil disobedience on Monday, but have not offered specific details.

___

Associated Press writer Jim Suhr and photographer Jeff Roberson contributed to this report.