FERGUSON, Mo. (AP) — Gov. Jay Nixon says his decision to draw down the Missouri National Guard in Ferguson follows progress in stemming upheaval in the St. Louis suburb since a white police officer fatally shot an unarmed black 18-year-old.

Nixon tells KMOX-AM that “the last two nights have been really good” in the suburb that had been the center of nightly racial unrest since Michael Brown was killed Aug. 9.

The white officer who shot Brown, Darren Wilson, is on administrative leave and has not been charged.

Nixon announced what he called a systematic withdrawal of Guard officers on Thursday. He says they’ve effectively protected the city while other agencies worked to restore trust between law enforcement and residents.

Authorities have arrested at least 163 people in the protest area since Brown’s death.

Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.