Demonstrators march through the streets during a protest over the shooting death of Michael Brown in Clayton, Missouri, November 17, 2014. [Photo/Agencies]

FERGUSON, Mo.- Missouri's governor declared a state of emergency on Monday and authorized the state's National Guard to support police in case of violence after a grand jury decides whether to indict a white police officer who fatally shot an unarmed black teenager.

"As part of our ongoing efforts to plan and be prepared for any contingency, it is necessary to have these resources in place in advance of any announcement of the grand jury's decision," Governor Jay Nixon said in a statement. The order also puts the St. Louis County Police Department, rather than police in Ferguson, Missouri, in charge of policing protests.

Residents of Ferguson, which saw weeks of sometimes violent protests following the Aug 9 shooting death of 18-year-old Michael Brown, are braced for the possibility of more unrest, particularly if the grand jury decides not to criminally charge Ferguson police officer Darren Wilson.

The past two days have seen protests around the area in anticipation of the grand jury's report. Several dozen demonstrators took to the streets on Monday in Clayton, Missouri, where a grand jury is meeting.

"We want an indictment. The cops don't like it," the protesters chanted as they marched in freezing temperatures.

"Something about the way Mike Brown was killed started a fire in me that I can't ignore," said one of the demonstration's organizers, Dhorbua Shakur, 24.

He said he had little sympathy for area residents who are tired of the demonstrations, which left some businesses in Ferguson burned out.

"They can turn this off and on with a TV screen. But this is my reality. This is my life," Shakur said.