Authorities declared a state of emergency in Ferguson, Missouri, on Monday in an effort to quell a repeat of the violence that erupted during demonstrations overnight to mark the police shooting of an unarmed black man one year ago.

The order was issued for the St. Louis suburb and surrounding areas amid already tense relations between residents and police after officers shot and critically wounded an 18-year-old man in an exchange of gunfire that marred what had been a day of peaceful demonstrations.

Prosecutors charged the man, Tyrone Harris, who was in critical condition, with four criminal counts, including "assault on law enforcement" and shooting at a motor vehicle. His bond was set at $250,000.