Missouri Gov. Jay Nixon (D) declared a state of emergency and a curfew from midnight to 5 a.m., in Ferguson, Mo., on Saturday.
"We will not allow a handful of looters to endanger the rest of this community,” Nixon said at a news conference in Ferguson. “If we're going to achieve justice, we must first have and maintain peace.”
Nixon earlier in the week replaced the St. Louis County police, who had been criticized for using tear gas and rubber bullets on protesters, with the Missouri Highway Patrol, who took a more hands-off approach.
“We won’t enforce it with trucks, we won’t enforce it with tear gas, we will enforce it with communication,” Captain Ron Johnson, the officer commanding the highway patrol in the city, said. “We will be telling people, 'It’s time to go home.'”
Earlier on Saturday, Rep. Lacy Clay (D-Mo.) and Sen. Claire McCaskill (D-Mo.) took to Twitter to urge that the actions of a few looters should not be allowed to overshadow peaceful protestors.
About 200 protesters threw rocks and other objects at police on Friday as others looted the convenience store police say Brown robbed before the shooting, according to the Associated Press.
Police also released a surveillance video Friday of the alleged robbery. The focus on Brown's actions before the encounter where he was shot drew the condemnation of Clay.
"They have attempted to taint the investigation," the congressman told protesters through a bullhorn, according to the AP. "They are trying to influence a jury pool by the stunt they pulled today."
The Justice Department said the FBI had conducted interviews with witnesses as part of its investigation into Brown's death.
This post was updated at 5:44 p.m.