BOULDER, Colo. — Firefighters made progress Sunday in battling a wildfire that forced people to flee hundreds of homes in the mountains just outside downtown Boulder, Colorado, and authorities said they believe the blaze may have been human-caused.

Light winds pushed the flames in the wooded area a couple of miles west of Pearl Street, the shopping and dining hub in the heart of the university city. Crews partially contained the fire that had burned just over 60 acres, but officials worried that stronger gusts that could fan the flames might develop overnight.

The Boulder Office of Emergency Management said 426 homes were evacuated before dawn and residents of an additional 836 were warned to get ready to leave if conditions worsened. The evacuation orders will remain in place overnight, Boulder County Sheriff’s Cmdr. Mike Wagner said.

There were no reports of injuries or damage to homes, emergency officials said. Several aircraft were dropping water and retardant on the flames, and a community center opened as an evacuation shelter.

Wagner said the area is used by hikers and by transients for camping, leading authorities to believe the blaze was human-caused. Wagner said officials ruled out any lightning strikes or downed power lines.