At least six people were injured as severe thunderstorms moved across parts of Oklahoma early Sunday, with tornadoes and flooding reported overnight, authorities said.

The six people injured were taken to the hospital with non-life-threatening injuries, said Valerie Littlejohn, public information officer with the Oklahoma City Police Department.

Several structures were also damaged in the area, along with power lines, trees, gas lines, traffic signals, and traffic signs, she said.

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.

About 95,000 customers in Oklahoma were without power Sunday morning, according to poweroutage.us.

Tornadoes were reported just east of Oklahoma City, and tornado and thunderstorm warnings are in place in the Oklahoma City area, the National 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 Oklahoma Department of Emergency Management said it is monitoring the severe weather.

Flooding on Interstate 35 closed all but one northbound lane near Forest Park in the Oklahoma City area, the Oklahoma Department of Transportation said.

The Oklahoma City Fire Department responded to several vehicles that were flooded due to heavy rainfall, according to the department’s public information officer Scott Douglas.

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

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.

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.