A massive tornado has touched down in Oklahoma as part of a major storm threatening almost the entire American Midwest, reported NBC News, citing a helicopter pilot with a local affiliate.
The National Weather Service has said several counties in central Oklahoma are at risk and Reuters reported the twister touching down on Monday in Moore, an Oklahoma City enclave.
There were no immediate reports of injuries or fatalities in Moore.
Twisters wreaked havoc in Oklahoma City and in Wichita, Kansas on Sunday. At least two elderly people were killed in storm-related incidents over the weekend.
Tens of millions of people have been told to prepare for extreme storm activity, said NBC, listing as many as 55 million people at risk in several US states.
Here's a video report from NBC: