The Wisconsin National Guard has been activated in Milwaukee Sunday in response to violence and protests that erupted there overnight after a man was fatally shot by police.

"I have activated the Wisconsin National Guard to be in a position to aid local law enforcement upon request," Wisconsin Gov. Scott Walker said in a statement Sunday.

Walker announced the National Guard activation after a request from Milwaukee County Sheriff David Clarke, who met with Walker and Wisconsin National Guard Adjutant General Donald Dunbar.

Volunteers spent the morning sweeping and picking up debris — including bricks, bottle and bullet casings — after about 100 protesters clashed with a couple of dozen officers in a north Milwaukee neighborhood, NBC News reports.

"I commend the citizens who volunteered in clean-up efforts this morning," Walker said. This act of selfless caring sets a powerful example for Milwaukee's youth and the entire community. I join Milwaukee's leaders and citizens in calling for continued peace and prayer."