(VOVworld) - Authorities declared a state of emergency in Ferguson, Missouri, on Monday to prevent a repeat of the violence that erupted Sunday night during protests of the police shooting of an unarmed black man one year ago that ignited a national firestorm on race relations.

St. Louis County Police Chief Jon Belmar said that Sunday's gunfire began with two groups of agitators apparently shooting at each other before one gunman darted across a parking lot and was confronted by four officers who pulled up in an unmarked vehicle. The suspect opened fire on the police vehicle and was badly wounded in the ensuing foot chase and exchange of gunshots with the four detectives. Jon Belmar said that the shooters were criminals, not protesters.