SAN FRANCISCObingoshowdownfree, June 28 (Xinhua) -- Air tankers and helicopters on Friday helped fight a wildfire northeast of Phoenix, Arizona, local officials said.

Near Phoenix, where the high temperature reached 110 degrees Fahrenheit (43 Celsius) on Friday, about 60 residents were evacuated from the Boulder Heights subdivision overnight after the human-caused fire broke out Thursday afternoon about 5 miles (8 km) east of Carefree, on the edge of the Tonto National Forest.

Arizona fire officials said that 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.

While the flames threatened scores of homes and forced dozens of residents to evacuate, there were no immediate reports of any injuries or structure damage, fire officials said, adding that they were investigating exactly what sparked the blaze.

The Red Cross set up an evacuation center at a high school in Scottsdale.

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

The National Weather Service said above-normal temperatures will persist well into next week.■