Air tankers and helicopters attack Arizona wildfire that has forced evacuations near Phoenix

SCOTTSDALE, Ariz. — Air tankers and helicopters helped douse flames from the sky as nearly 200 firefighters on the ground battled a wildfire northeast of Phoenix on Friday that threatened scores of homes and forced dozens of residents to evacuate.

Authorities expanded the evacuation area in a subdivision on the northeast outskirts of Scottsdale, closed roads and shut down part of a nature preserve as gusty winds continued to fan the flames in extremely hot, dry conditions.

But there were no immediate reports of any injuries or structure damage, Arizona fire officials said.

Near Phoenix, where the high reached 110 degrees Fahrenheit (43.3 Celsius) on Friday, about 60 residents evacuated homes in the Boulder Heights subdivision overnight after the human-caused fire broke out at about 2:30 p.m. Thursday.

Fire officials said they were investigating exactly what sparked the blaze about 5 miles (8 kilometers) east of Carefree, just outside northern Scottsdale on the edge of the Tonto National Forest.

Dubbed the Boulder View Fire, it has burned about 5 square miles (13 square kilometers) with zero containment, authorities said.

''The southeast side of the fire remained active throughout the night producing 20-40 foot flame lengths in areas,'' Tiffany Davila, a spokesperson for the Arizona Department of Forestry and Fire Management, said in a statement.

The Red Cross set up an evacuation center at a high school in Scottsdale, and shelters for horses and other large animals were established at several locations, including the rodeo grounds at nearby Cave Creek.

Scottsdale officials closed part of the McDowell Sonoran Preserve as a precaution but said there was no immediate threat. The air tankers armed with red retardant and helicopters hauling giant buckets of water helped ground crews keep the flames away from power lines in the area so far, fire officials said.

The National Weather Service said above-normal temperatures will persist well into next week, with many lower desert locations seeing highs near or exceeding 110 degrees F (43.3 C) each afternoon.

Meanwhile in central Oregon, fire officials were releasing some crews from the lines south of Bend because conditions have improved and the threat posed by a wildfire to the community around La Pine has decreased after hundreds were evacuated earlier this week.

Firefighters said Friday they had dug fire lines around nearly half of the Darlene 3 fire, near La Pine, which has now burned an estimated 6 square miles (15.5 square kilometers) and was listed at 42% containment.