Police and protesters continue to clash outside of St. Louis, Missouri, over the death of an unarmed black teenager.
Michael Brown, 18, was shot and killed after a scuffle with a police officer in Ferguson, Missouri, on Saturday.
On Monday night, police in riot gear fired tear gas and rubber bullets into a crowd of protesters after they threw rocks at them.
Over the weekend, angry mobs kicked in windows, looted stores and smashed police cars.
Vandals also spray painted the words "the only good cop is a dead cop."
National NAACP President Cornell William Brooks implored residents to "turn your anger into action" while condemning violence in response to Brown's death.
"To sneak around under the cover of darkness, to steal, to loot, to burn down your neighborhood - this does not require courage," he said. "Courage is when you strive for justice."
"Martin Luther King did not live and die so that we may steal and lie in the middle of the night," he added.
Witnesses to Saturday's shooting said Brown had his hands raised when the officer approached with his weapon drawn and fired repeatedly.
But police said someone involved in the incident tried to grab the officer's gun.
Some civil rights leaders have drawn comparisons between Brown's death and that of 17-year-old Trayvon Martin, who was fatally shot by a Florida neighborhood watch organizer who was later acquitted of murder charges.
"Instead of celebrating his future, they are having to plan his funeral," said Benjamin Crump, a family attorney who also represented Martin's relatives after he was slain in 2012 in Florida.
"I don't want to sugarcoat it," Crump added. Brown "was executed in broad daylight."
The FBI has opened an investigation into Brown's death.