FERGUSON, Mo. -- A man is in critical condition after he was shot during overnight protests in Ferguson, Missouri, State Highway Patrol Capt. Ron Johnson told reporters early Sunday.

Police also used tear gas on the small group of demonstrators who defied a local curfew that ran from midnight to 5 a.m., Johnson said, because they believed a person was armed. Seven people were arrested, he said.

Announced Saturday by Gov. Jay Nixon (R), the curfew was meant to curb the looting that's accompanied uproar over the death of unarmed teen Michael Brown at the hands of police over a week ago in this St. Louis suburb. Nixon also declared a state of emergency.

Police and civilians have clashed since the Aug. 9 death, but tensions eased for one night after state highway patrol officers stepped in to keep the peace in the place of the local police force, which had taken a militarized approach to protesters. But violence again flared this weekend, after authorities released a video allegedly showing Brown robbing a convenience store before he was shot.

As the midnight deadline approached on Saturday, the crowd in the streets appeared to be younger than on previous nights. The mood early in the evening was also more antagonistic than usual.

A strange party-like atmosphere took hold in the area around QuikTrip, the convenience store that was set on fire in the first night of unrest after Brown's death. Some people were drinking in the street, and the smell of marijuana wafted through the air. The streetlights around the store were out of operation, and most of the camera crews were packing up.

Cars drove down the street playing loud music and doing donuts, with people riding on the roof of one of the cars. Chants of "fuck the police -- we ain't never going home" came from another.

"The mixture is not helpful at all," Rebecca McCloud, a missionary at Son Lake Ministries in East St. Louis who came to Ferguson as a peacekeeper, said. "They're under the influence of something that's going to tell them they're strong."

Things looked peaceful when the clock first struck 12. Most people had dispersed, likely in part due to rain and community peacekeeping efforts.

But less than an hour after the curfew began, approximately 70 officers formed a line with their shields raised. They donned masks and fired smoke and tear gas at the remaining protesters. Police initially said that they were smoke bombs, but reporters found tear gas canisters, and protesters insisted their eyes burned. Later on, police confirmed to The Huffington Post that tear gas was used.

Smoke grenades are lobbed at protestors. pic.twitter.com/S23JbPlcbe — Jim Ryan (@jimryantx) August 17, 2014

Reporters on the scene said there was a gunshot fired.

"Shit shit shit. Those are shots. I just heard a bullet... I just heard something whiz past me." -- @vicenews#Ferguson — Jennifer Bendery (@jbendery) August 17, 2014

Man shot in leg. Just taken to hospital in car pic.twitter.com/DdMBc9l0vp — Jon Swaine (@jonswaine) August 17, 2014

Multiple reporters and witness say someone was shot in the neck. Unclear what kind of bullets. — Byron Tau (@ByronTau) August 17, 2014

Johnson addressed the media early on Sunday morning, after crowds had largely dispersed.

He noted that authorities were not aware of any looting taking place in Ferguson on Saturday night.

Johnson: I was disappointed with the actions of the crowd tonight. #ferguson — Joel Currier (@joelcurrier) August 17, 2014

Earlier in the night, there were signs that law enforcement and community members were developing a rapport. A masked protester confronted Johnson during a press conference in front of the Ferguson Mart and Liquor, the convenience store where Michael Brown was accused of stealing cigarettes. The protester yelled at Johnson, but Johnson engaged him in a conversation as he was starting to walk away.

Amazing moment now between Ron Johnson and a masked protestor." #Fergusonpic.twitter.com/6IGKZrZ1fR — Ryan J. Reilly (@ryanjreilly) August 17, 2014

"I need answers sir, like for real. I salute you, but ... why did that man get gunned down in cold blood?" the protester asked.

"There's people that are white, Hispanic and Asian, there's a lot of people out here protesting and we're asking for change. It's not just us, it's everybody," Johnson replied.

"We're going to get some answers, I promise you. I promise you," Johnson emphasized. The protester took off his mask in the course of the exchange and identified himself as Jason Ross.

"I could have just walked away. I could have ignored you," Johnson said to Ross. "And you know what? I know in the past you have been ignored."

Protestor is named Jason Ross. Here he is without his mask. pic.twitter.com/8kywh2Mzgu — Ryan J. Reilly (@ryanjreilly) August 17, 2014

"That walk they did will pass through Missouri all the way to the White House," Johnson said of the FBI probe.

"The long-term solution is healing," he continued. "We can walk these streets again when we remember that we have made some changes here that can impact this nation. The community's going to have to be involved in that transition, in how it works, and in making it work."

"I love y'all, I love this community, and I'm really honored to be standing here with you and talking with you and just being a part of this week and listening to your voice," Johnson said.

Community members said earlier on Saturday that they had mixed feelings about the curfew.

Renee Richardson, a black mother of three from Florence, Missouri, said she hoped that the curfew would hold.

"Midnight is a good time," Richardson said. "I just think they should keep the streets open and let people come and go as they please, that's the only objection I have."

Richardson's sons are all college graduates, she said, and all of them have had problems with the police.

"It's just a different thing if you're black," she said. "St. Louis is a racially prejudiced city. If you're not from here, you don't understand it, but everyone out here has had the same sort of problem."