YARNELL -- A fire information officer says 19 firefighters are unaccounted for while battling the Yarnell Hill Fire in a central Arizona community.
Mike Reichling told the Arizona Republic that 20 firefighters were involved in a "serious incident."
The newspaper reports that one of the firefighters has been located.
The Yavapai County Sheriff's Office has notified residents in the Peeples Valley area and in the town of Yarnell to evacuate.
Earlier Sunday, the fast-moving fire prompted evacuations of 50 homes in the Buckhorn, Model Creek and Double A Bar Ranch areas about 85 miles northwest of Phoenix.
In the afternoon, the Yavapai County Sheriff's Office expanded the evacuations to include residents in the Peeples Valley area and in the town of Yarnell.
The wildfire also forced the closure of parts of state Route 89, the Arizona Department of Transportation announced. The department did not have an estimate of how long the closure would last but advised drivers to use U.S. 93 or Interstate 17 as alternate routes.
The Red Cross has opened a shelter at Yavapai College in Prescott, the sheriff's office said.
The Yarnell Hill Fire now covers nearly 2,000 acres, according to the newspaper.
The fire started Friday but picked up momentum Sunday as the area experienced high temperatures, low humidity and windy conditions.
About two hundred firefighters are now working at the fire, but an additional 130 firefighters and more water- and retardant-dropping helicopters and aircraft are on their way.
In another Arizona fire, a 2-acre blaze that started at a motorcycle salvage yard and spread to a trailer park has destroyed five mobile homes in the Gila County community of Rye, located more than 130 miles east of Yarnell.
Gila County Health and Emergency Services Director Michael O'Driscoll said no one was injured in Rye.
The fire was ignited Saturday night at All Bikes Sales located off Highway 87. It spread to neighboring federal Forest Service land but was fully contained within 12 hours of its start.
The cause of the fire is under investigation.
Seven adults and two children were staying at a shelter set up for people who were evacuated, the Red Cross said.