The National Guard arrived in Ferguson but kept its distance from the streets where protesters collided again with police, as clouds of tear gas and smoke hung over the St. Louis suburb where unarmed black teenager Michael Brown was fatally shot by a white police officer.
Protesters filled the streets after nightfall Monday, and officers trying to enforce tighter restrictions at times used bullhorns to order them to disperse. Police deployed noisemakers and armored vehicles to push demonstrators back. Officers fired tear gas and flash grenades.
Capt. Ron Johnson of the Missouri Highway Patrol, who is in charge of security in Ferguson, said rocks, bottles and Molotov cocktails were thrown from the crowd and that some officers had come under heavy gunfire.
At least two people were shot and 31 were arrested, some from as far away as New York and California, he said. He did not have condition updates on those who were shot. Johnson said four officers were injured by rocks or bottles.
He said officers didn't fire any shots.
One peaceful demonstrator, Charles Bourrage, told CBS News correspondent Vladimir Duthiers that a small group of violent protesters were working against the message of the larger crowd.
"We grabbed those that were trying to move the violence forward and moved them back. We grabbed them literally," Bourrage said.
Two small fires were reported, one in a store and the other in a vacant home.
Johnson commended the conduct of the officers, saying they "acted with restraint and calm despite pockets of disorder and coming under violent attack on several occasions."
Citing "a dangerous dynamic in the night" that he said "allows a small number of violent agitators to hide in the crowd and then attempt to create chaos," Johnson urged protesters with peaceful intent to demonstrate during the daytime hours. He blamed the violence on "a tiny minority of lawbreakers."
Schools in Ferguson will be closed at least the rest of this week, district officials announced.
Demonstrators no longer faced the neighborhood's midnight-to-5 a.m. curfew, but police told protesters they could not gather in a single spot and had to keep moving. After the streets had been mostly cleared, authorities ordered reporters to leave as well, citing the risk from gunfire that had been reported.
A photographer for the Getty photo agency was arrested while covering the demonstrations and later released. Two German reporters were arrested and detained for three hours. Conservative German daily Die Welt said correspondent Ansgar Graw and reporter Frank Herrmann, who writes for German regional papers, were arrested after allegedly failing to follow police instructions to vacate an empty street. They said they followed police orders.
Johnson said members of the media had to be asked repeatedly to return to the sidewalks and that it was a matter of safety. He said in some cases it was not immediately clear who was a reporter but that once it was established, police acted properly.
The latest clashes came after a day in which a pathologist hired by the Brown family said the 18-year-old suffered a bullet wound to his right arm that may indicate his hands were up or his back was turned. But the pathologist said the team that examined Brown cannot be sure yet exactly how the wounds were inflicted until they have more information.
Witnesses have said Brown's hands were above his head when he was repeatedly shot by an officer Aug. 9.
The independent autopsy determined that Brown was shot at least six times, including twice in the head, the family's lawyers and hired pathologists said.
The St. Louis County medical examiner's autopsy found that Brown was shot six to eight times in the head and chest, office administrator Suzanne McCune said Monday. But she declined to comment further, saying the full findings were not expected for about two weeks.
A grand jury could begin hearing evidence Wednesday to determine whether the officer, Darren Wilson, should be charged in Brown's death, said Ed Magee, spokesman for St. Louis County's prosecuting attorney.
A third and final autopsy was performed Monday for the Justice Department by one of the military's most experienced medical examiners, Attorney General Eric Holder said.
Holder was scheduled to travel to Ferguson later this week to meet with FBI and other officials carrying out an independent federal investigation into Brown's death.
The Justice Department has mounted an unusually swift and aggressive response to Brown's death, from the independent autopsy to dozens of FBI agents combing Ferguson for witnesses to the shooting.
In Washington, President Obama said the vast majority of protesters in Ferguson were peaceful, but warned that a small minority was undermining justice. Mr. Obama said overcoming the mistrust endemic between many communities and their local police would require Americans to "listen and not just shout."
Obama said he also spoke to Missouri Gov. Jay Nixon about his deployment of the National Guard in Ferguson and urged the governor to ensure the Guard was used in a limited way.
Brown family attorney Benjamin Crump said Brown's parents wanted the additional autopsy because they feared results of the county's examination could be biased. Crump declined to release copies of the report.
"They could not trust what was going to be put in the reports about the tragic execution of their child," he said during Monday's news conference with Parcells and Baden, who has testified in several high-profile cases, including the O.J. Simpson murder trial.
The second autopsy, Crump said, "verifies that the witness accounts were true: that he was shot multiple times."
Forensic pathologist Shawn Parcells, who assisted former New York City chief medical examiner Dr. Michael Baden during the private autopsy, said a bullet grazed Brown's right arm. He said the wound indicates Brown may have had his back to the shooter, or he could have been facing the shooter with his hands above his head or in a defensive position across his chest or face.
"We don't know," Parcells said. "We still have to look at the other (elements) of this investigation before we start piecing things together."
Baden said one of the bullets entered the top of Brown's skull, suggesting his head was bent forward when he suffered that fatal injury. The hired pathologists said Brown, who also was shot four times in the right arm, could have survived the other bullet wounds.
Baden also said there was no gunpowder residue on Brown's body, indicating he was not shot at close range. However, Baden said he did not have access to Brown's clothing, and that it was possible the residue could be on the clothing.
Crump also noted that Brown had abrasions on his face from where he fell to the ground, but there was "otherwise no evidence of a struggle."