Damaged homes in an Oklahoma City area neighborhood are seen in this aerial image.
CNN  — 

Tornadoes and flooding spawned by severe thunderstorms tore through parts of Oklahoma overnight, leaving at least 11 people injured and shredding homes and other properties.

Residents in Oklahoma and Texas are bracing for more severe weather Sunday, including possible tornadoes, flash floods, hail and strong winds.

The National Weather Service issued warnings for parts of both states Sunday afternoon. The severe weather is expected to move from west to east Sunday, the weather service said.

Eleven people were taken to the hospital with non-life-threatening injuries after the storms overnight, said Scott Douglas, public information officer with the Oklahoma City Fire Department. Several others suffered minor injuries but declined to seek medical treatment.

Several structures were damaged in the area, along with power lines, trees, gas lines, traffic signals, and traffic signs, said Valerie Littlejohn, public information officer with the Oklahoma City Police Department.

As of 1:30 p.m. CST Sunday, 39 structures had been destroyed, according to Oklahoma City officials. Additionally, 43 structures sustained major damage, while 54 had minor damage.

More than 20,000 customers in Oklahoma and Texas were without power Sunday afternoon, according to PowerOutage.us. In Oklahoma City alone, 5,000 residents were without power as of Sunday afternoon, according to the city.

Oklahoma Gov. Kevin Stitt issued an emergency declaration for six counties, he announced at a news conference Sunday.

Officials are working to ensure polling stations across the state have power ahead of the presidential election Tuesday, Stitt said. “We’ll advise the public if there’s any issue there with the polling stations and reroute people if need to,” the governor said.

Local fire crews as well as National Weather Service teams are surveying the damage Sunday, including in the town of Valley Brook, Harrah and Newcastle where the storms caused severe destruction.

Video of the damage from CNN affiliate KOCO shows cars overturned and whole houses shredded. The storms toppled telephone poles and snapped trees in half. Debris is scattered around impacted areas, including large pieces of wood and metal from buildings that were ripped apart.

Around 1:20 a.m., the weather service warned a severe thunderstorm with a tornado was moving through eastern Oklahoma City toward Midwest City and Tinker Air Force Base. A tornado warning was issued for over 300,000 people in Moore, Midwest City and Del City.

“I was awake, and I heard it pick up very quickly,” said Justin Cue, describing the moment a possible tornado struck his father’s home overnight, leaving him with minor injuries from flying glass and debris.

“Debris started hitting the house, and after a few seconds my window blew out and then all you could hear was the roar of the wind and the ripping wood and glass shattering,” Cue told CNN.

Cue’s father, who moved to Oklahoma City from Kansas about two years ago, was also injured when the roof collapsed on him. “He was unconscious for a brief time and we weren’t sure he was OK,” Cue said.

When the pair was able to get out of the home around 1:30 a.m., Cue said neighbors were yelling and helping get people out of the rubble until first responders arrived.

Tornadoes were reported just east of Oklahoma City, and tornado and thunderstorm warnings were in place through early morning in the Oklahoma City area, the weather service said.

“Folks, don’t let your guard down too much – we’re already starting to see the atmosphere begin to recover ahead of yet another round of thunderstorms, heavy rainfall, flooding, and potential severe weather today,” the weather service said in a post on X.

The National Weather Service issued a tornado watch for parts of Oklahoma and a few counties in northern Texas until 8 p.m. CST Sunday. The watch includes Oklahoma City and surrounding cities southeast, affecting more than two million people.

Supercell thunderstorms are firing off the same front that caused damage overnight. These new storms are capable of a few tornadoes, ping pong ball-sized hail, and 75 mph damaging winds.

“Clusters of intense thunderstorms over southwest Oklahoma and northwest Texas will track rapidly northeastward this afternoon across the watch area. Strong low-level shear will support a risk of tornadoes and damaging wind gusts with these storms,” according to the weather service’s Storm Prediction Center.

The Oklahoma Department of Emergency Management said it is monitoring the severe weather.

Cars were overturned by the severe storms in Oklahoma.

Police are asking people to avoid some roads in the area due to the damage.

First responders rescued two people trapped inside an overturned mobile home after the storms hit, according to the Oklahoma City Fire Department. They also responded to several vehicles that were flooded due to heavy rainfall, according to Douglas.

The University of Oklahoma told students and staff on its Norman campus to “Seek shelter NOW inside the building you are in. Move to lowest floor/interior.”

Nighttime tornadoes are more than twice as deadly as daytime ones, research shows. Nocturnal tornadoes are difficult to spot in the darkness and those sleeping may not be aware that danger is near.

National Weather Service teams are surveying the damage Sunday morning.

There’s heightened concern over the tornado threat this week given how prolific a year it has been for twisters in the US. The number of tornadoes reported so far this year is the second-most on record, trailing only 2011’s 2,156.

Violent thunderstorms are most common in spring and summer, but a second surge of dangerous storms and tornadoes happens during fall and winter as cold air from the north often collides with warmer, moist air streaming out of the Gulf of Mexico.

CNN’s Mike Madrigal, Elisa Raffa and Kia Fatahi contributed to this report.