Cooke County, Texas - At least five people were killed in northern Texas after a tornado hit the state overnight, destroying buildings and a gas station and overturning trucks, local media reported early Sunday.

Rescue efforts were ongoing and hundreds of thousands of people were without power after the storms across the Southern Plains region, with towns in Oklahoma and Arkansas also reportedly affected.

Cooke County Sheriff Ray Sappington said at least five people were dead after a tornado ripped through Texas.

"We do have five confirmed [dead], but sadly, we think that number is probably going to go up," Sappington reported.

"We're still in search and rescue mode right now... I hope we can still find survivors," he told ABC affiliate WFAA.

Sappington spoke in front of a travel center – a highway rest stop with a gas station and some restaurants – where he said around 60-80 people, some seeking shelter, had been when the winds hit.

There had been "a lot" of injuries, he said, though none there were life-threatening.

Some 375,000 people were without power early Sunday in Texas, Missouri, Oklahoma, Kansas, and Arkansas, according to the website Poweroutage.us.

More severe weather was predicted for the Great Plains region Sunday with tornado alerts still in many places, but in Texas the National Weather Service said the threat had diminished.

"It'll rebuild," Sappington told WFAA. "It's Texas."