Masked individuals carry items out of a store, during on-going demonstrations to protest against the shooting of Michael Brown, in Ferguson, Missouri, Aug 16, 2014. [Photo/Agencies]

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.

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.

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."