Borger, Texas ? Using bulldozers and air tankers, firefighters struggled Monday to stop wind-blown wildfires that scorched more than 1,000 square miles of the drought-stricken Texas Panhandle.

The blazes were blamed for at least seven deaths, four of them in a crash on a smoke-shrouded highway over the weekend. Four more bodies were found Monday evening in a car that had crashed into a ravine, and authorities suspected those deaths also were caused by the wildfires.

About 1,900 people in seven counties were evacuated.

“This has been a very deadly wildfire season, but Texas communities have shown strength, and we’re going to continue fighting these fires from the ground and from the air,” said Rachael Novier, a spokeswoman for Gov. Rick Perry.

There was no immediate estimate of the number of homes damaged or destroyed. Firefighters used bulldozers to plow fire breaks in the parched earth, while air tankers dropped water on the flames.

Eleven fires burned across an estimated nearly 700,000 acres Monday, up from 663,000 over the weekend. State fire crews fought more than 160 blazes in one 24-hour period.

In this photo provided by the Borger Emergency Operations Center, flames from a wildfire leap into the sky in the Texas Panhandle near Borger, Texas, Sunday, March 12, 2006.

The size of the scorched area easily eclipsed the 455,000 acres that burned in December and January, when the governor declared a disaster.

The cause of the latest blazes was under investigation.

Four people were killed Sunday in a chain-reaction accident involving nine vehicles on a smoky Interstate 40 near Groom, about 40 miles east of Amarillo. Three people died in fires near Borger – two of them trying to escape a grass fire that consumed their home, said fire Capt. Mike Galloway.

“The brush fire overtook their house and yard and got them,” he said. “The flames just spread so fast.”

Monday evening, four bodies were found in a car that had run off a road into a ravine in Roberts County.

Authorities said early evidence suggested the deaths were linked to the grass fires.

The fires were fanned by the same storm system that caused deadly tornadoes and storms in the Midwest.