Washington, May 27 (BBC) - At least 18 people were killed as tornadoes and storms tore across central areas of the US, destroying homes and cutting power to hundreds of thousands.

Seven people were killed in northern Texas, eight in Arkansas, two in Oklahoma and one in Kentucky. Scores more were injured, and almost 500,000 were without electricity across several states on Sunday.
Texas Governor Greg Abbott said more than a third of all counties in his state were now subject to a disaster declaration.

Sheriff Ray Sappington of Cooke County, Texas, said the death toll there included two children aged two and five and three members of the same family.

"It's just a trail of debris left," said the sheriff of Valley View area, which was among those hardest hit by a powerful tornado. "The devastation is pretty severe."

Footage from the county showed a petrol station and rest stop almost completely destroyed, with twisted metal littered over damaged vehicles.

Twisters overturned lorries, shut a highway near Dallas and left tens of thousands of people without power throughout the region. Lightning, thunder and heavy rain meanwhile forced the evacuation of around 125,000 spectators as Sunday's Indianapolis 500 race was delayed by four hours.