Firefighters continued to battle a wind-whipped wildfire in the hills just east of Anaheim Hills tonight as the California Highway Patrol shut down the 241 toll road near the Windy Ridge exit, according to authorities.

The fire erupted on the eastern side of the tollway, separating it from tracts of homes on the western side. Crews were hoping to keep the fire confined to the east side, fire officials said. Ground crews were trying to lay hose lines to beat back the flames on its flanks.

Lanes were also closed on the 91 Freeway, just north of the blaze.

[Updated 11:23 p.m.:The blaze has burned at least 25 acres, fire officials said. At least 15 fire engines are at the scene with additional units on the way.

Winds are blowing 15 to 25 mph, officials said. But so far, crews have been able to confine the flames to the east side of the toll road.]

“It’s got some potential to spread,” said Battalion Chief Kris Concepcion of the Orange County Fire Authority.

[Updated 11:23 p.m: "We want to keep it to the east side of the toll road because the threat is on the west side," Concepcion said.]

Flames were a couple of miles from the nearest structures, but residents were advised to have escape plans in case they have to leave, said Capt. Greg McKeown of the Orange County Fire Authority.

The National Weather Service issued a red flag warning for Orange County and other regions of Southern California. Winds were expected to gust as high as 50 mph, with relative humidity in the single digits, the Weather Service said.

Water could be an issue in the area, and fire commanders were calling for water tankers to help supply engine trucks, officials said.