At least two people have been killed after a tornado tore through the city of El Reno in Oklahoma, destroying a hotel and damaging a mobile home park, officials said.
The tornado struck the south-east of El Reno at about 22:30 local time (03:30 GMT) on Saturday.
El Reno Mayor Matt White said several people were being treated in hospitals and rescue efforts were ongoing.
He described the damage caused by the tornado as “pretty devastating”.
Speaking at a press conference on Sunday, Mr White urged people to stay away from the area, where local businesses were also damaged.
He said officials would release more details about the identities of those killed after family members had been notified.
He would not give details on how many people were injured, but said officials “know there are some serious injuries at this point in time”.
“El-Reno has suffered in the past couple of weeks [from] some significant flooding,” Mr White added, as he called on people to offer prayers to those affected.
A number of severe weather warnings are currently in place for areas across Oklahoma.
The incident on Saturday follows a week of tornadoes, severe rain and flooding in states in the Southern Plains and Midwest regions.
The recent spate of extreme weather has been blamed for at least nine deaths across the region, the Associated Press reports.
Local police chief Richard Stephens said Saturday night was an “unfortunate example of just how quickly these types of storms can develop from a simple thunderstorm into a deadly supercell tornado”.
Experts from the National Weather Service have begun assessing the damage, and say they have currently classified the tornado as EF2 on the Fujita scale, which means it had peak winds of at least 111 mph (178 kph).