FERGUSON - Missouri Gov. Jay Nixon declared a state of emergency and imposed a curfew Saturday in the St. Louis suburb where a black teenager was shot to death by a white police officer a week ago.

Protesters shout slogans during a demonstration in Ferguson, Missouri, the United States, on Aug 15, 2014. [Photo/Xinhua]

Guide to developments in Missouri police shooting Associated Press Missouri Highway Patrol seizes control of Ferguson Associated Press Protesters gather in Ferguson, carry signs, chant Associated Press How Capt. Ron Johnson changed police tactics in wake of Mike Brown shooting Christian Science Monitor Missouri governor declares emergency, sets curfew in Ferguson Reuters Nixon said that though many protesters were making themselves heard peacefully, the state would not allow a handful of looters to endanger the community. The curfew will run from midnight to 5 am.

Tensions in Ferguson flared late Friday after police released the name of the officer who fatally shot 18-year-old Michael Brown and documents alleging Brown robbed a store before he died.

Nixon also said the US Department of Justice is beefing up its investigation of the shooting.

Missouri State Highway Patrol Capt. Ron Johnson, who is in charge of security in Ferguson, said there were 40 FBI agents going door-to-door talking to people who might have seen or have information about the shooting.

Nixon and Johnson spoke at a church in Ferguson, where they were interrupted repeatedly by people demanding justice and objecting to the curfew.

Fatal shooting of teenager sparks protests Masked individuals carry items out of a store, during on-going demonstrations to protest against the … Johnson assured those in attendance that police would communicate with protesters and give them ample opportunity to observe the curfew.

"You saw people sitting in the street and they had the chance to get up," he said. "And that's how it's going to continue."

Brown's death had already ignited several days of clashes with furious protesters. Tensions eased Thursday after Nixon turned oversight of the protests over to the Missouri Highway Patrol. Gone were the police in riot gear and armored vehicles, replaced by the new patrol commander who personally walked through the streets with demonstrators. But Friday night marked a resurgence of unrest.

Local officers faced strong criticism earlier in the week for their use of tear gas and rubber bullets against protesters. Johnson said one tear gas canister was deployed Friday night after the group of rioters became unruly.

The officer who killed Brown was identified as 28-year-old Darren Wilson, a six-year police veteran who had no previous complaints filed against him.

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.

St. Louis County Executive Charlie Dooley asked Missouri Attorney General Chris Koster on Friday to take over the case, saying he did not believe McCulloch could be objective. Koster said Missouri law does not allow it unless McCulloch opts out, and McCulloch spokesman Ed Magee said the prosecutor has no plans to surrender the case.