Updated

Authorities are setting up a designated protest zone for nightly demonstrations in Ferguson, Missouri.

The plan was announced Monday by St. Louis County police. Spokesman Brian Schellman says authorities are encouraging peaceful protesters to stay in the zone.

But it wasn't clear what would happen to those who refuse to go into the designated area along West Florissant Avenue, where the majority of protests have occurred.

The shooting death of 18-year-old Michael Brown by a Ferguson police officer on Aug. 9 has spurred several protests and confrontations with police. Early Monday, Missouri Gov. Jay Nixon activated the National Guard to help maintain order.