ASSOCIATED PRESS - Police said they fired smoke and tear gas canisters into a crowd of defiant protesters who gathered in a St. Louis suburb early Sunday where a black teen had been shot by a white police officer while walking down the street.
Hundreds of other protesters left peacefully before the midnight to 5 a.m. deadline took effect in Ferguson, Missouri, where 18-year-old Michael Brown had been shot Aug. 9.
But remaining protesters — chanting "No justice! No curfew!" — refused to leave the area. As five armored tactical vehicles approached the crowd, officers spoke through a loudspeaker: "You are in violation of a state-imposed curfew. You must disperse immediately. Failure to comply, may result in arrest."
As officers put on gas masks, a chant from the distant crowd emerged: "We have the right to assemble peacefully."
A moment later, police began firing canisters into the crowd of protesters.
Highway Patrol Spokesman Lt. John Hotz initially said police only used smoke, but later told The Associated Press that they also fired tear gas canisters. He said of police efforts: "Obviously, we're trying to give them every opportunity to comply with the curfew."
Jayson Ross, who was leading the protesters toward police before the canisters were fired, said: "They got guns. We got guns. We are ready."
The unrest between police and protesters came after Gov. Jay Nixon on Saturday declared a state of emergency in Ferguson.
Nixon's curfew announcement came after tensions again flared in Ferguson late Friday night. Earlier that day, local police identified the officer who shot Brown as Darren Wilson and released documents and video footage alleging that Brown had robbed a convenience store just before he was shot. Police said Wilson was unaware Brown was a suspect when he encountered him walking in the street with a friend.
Nixon said the U.S. Department of Justice is widening its civil rights investigation of the shooting.
Missouri State Highway Patrol Capt. Ron Johnson, who is in charge of security in Ferguson, said 40 FBI agents were going door-to-door in the neighborhood starting Saturday, talking to people who might have seen or have information about the shooting.
Brown's death ignited several days of clashes with furious protesters. Local officers faced strong criticism for their use of tear gas and rubber bullets against protesters.
As the curfew approached late Saturday night, New Black Panther Party leader Malik Shabazz roamed the street with a bullhorn, encouraging people to leave for their own safety. Many appeared to follow his suggestion.
Crowds that were in the hundreds prior to the curfew dwindled significantly in the final hour.
In announcing the curfew, Nixon said that though many protesters were making themselves heard peacefully, the state would not allow looters to endanger the community.
"We must first have and maintain peace. This is a test. The eyes of the world are watching," Nixon said. "We cannot allow the ill will of the few to undermine the good will of the many."
Darrell Alexander, 57, worried Saturday night that the curfew might spur anger and more violence.
"I think it's an antagonistic decision to not allow people to express their freedom of speech. It's an overreaction," he said.
On Saturday, some residents said it appeared the violent acts were being committed by people who came from other suburbs or states.
"Who would burn down their own backyard?" asked Rebecca McCloud. "These people aren't from here. They came to burn down our city and leave."
Wilson, the officer who shot Brown, is a six-year police veteran who had no previous complaints against him, the local police chief has said.
The Ferguson Police Department has refused to say anything about Wilson's whereabouts, and Associated Press reporters were unable to contact him at any addresses or phone numbers listed under that name in the St. Louis area.
Wilson has been on paid administrative leave since the shooting. St. Louis County prosecutor Bob McCulloch said it could be weeks before the investigation wraps up.