Firefighters are continuing to reign in the Sawmill Fire, burning south of Tucson. The blaze is now 40 percent contained, after burning more than 70 square miles.

But high wind today could hamper fire suppression efforts, with gusts of up to 35 miles per hour expected.

On Thursday, high winds forced officials to ground firefighting aircraft.

The wildfire has already crossed one mountain range since it started Sunday, about 10 miles southeast of Green Valley.

No injuries or damage to homes have been reported, but many evacuations and pre-evacuations have been ordered.

Authorities said Thursday that an off-duty U.S. Border Patrol agent is being investigated for possibly starting the fire while practice shooting.