Tornado-spawning storms swept across parts of the central United States, killing at least a dozen people and leaving a trail of destruction as forecasters warned of more severe weather over the Memorial Day holiday weekend.

At least seven people, including children, were killed in Texas when a powerful tornado struck communities in the north central part of the state near the Oklahoma border on Saturday night, Ray Sappington, the sheriff of Cooke County, said.

Two children, aged two and five, were among the victims, Sappington said. Numerous injuries were reported, Cooke County officials said.

As the scale of the disaster came into full view on Sunday, officials were wrapping up search and rescue operations.

The sheriff said some of the many trailer homes in the hardest-hit area were "completely gone" and others had suffered massive damage from the storm which Sappington estimated left a quarter-mile wide path of destruction for three to four miles.

A tornado also crossed into Denton County, northwest of Dallas, on Saturday night, damaging homes and other property, and knocking down power lines. Officials said that "a number of individuals" with injuries were transported to area hospitals.

Hundreds of thousands of customers were without power across a large swath of the country, including in Arkansas, Missouri and Texas on Sunday, according to poweroutages.us.

Officials in Arkansas also reported several storm-related fatalities, including one in Benton County, two in Marion County and a 73-year-old woman in Baxter county. Responding authorities described roads closed and clogged with debris, downed trees and power lines, homes and businesses destroyed, as well as numerous injuries.

Storms caused widespread damage and at least two fatalities in parts of Oklahoma, where officials activated an Emergency Operations Centre to coordinate efforts statewide.

In Indiana, adverse weather delayed the start of the famed Indianapolis 500-Mile Race, or Indy 500, car race.

The latest bout of extreme weather came just days after a powerful tornado ripped through a rural Iowa town, killing four people. (Reuters)