President Donald Trump has activated the National Guard in tornado-struck Arkansas after storms ripped through multiple states over the weekend, leaving at least 37 dead.

Thousands of power outages were reported Saturday as a deadly severe weather outbreak moved across the Midwest and South.

The most fatalities were in Missouri. Forecasters warned that tornadoes, hail and violent winds continue to threaten states in the Deep South, from Louisiana to Georgia.

Millions of Americans across the country are on alert for a severe weather outbreak as violent, long-track tornadoes with damaging winds of up to 80 mph and large hail are expected across the Midwest and South with the cross-country storm moving east.

Large and destructive tornadoes are carving paths of destruction across the South for the second day in a row.

Meanwhile, the severe weather threat will linger through Sunday from Florida northward into the upper Ohio River Valley, forecasters warned.

Violent tornadoes ripped through parts of the U.S., wiping out schools and toppling semitractor-trailers in several states.