Four dead after powerful storms slam Houston, Texas

Thunderstorms have killed four people and knocked out power to nearly a million homes and businesses in south-east Texas.

"We have a storm with 100 mph winds, the equivalent of Hurricane Ike, considerable damage downtown," said the mayor of Houston, John Whitmire.

Two deaths came from fallen trees and one from a crane blown over.

The storm has now moved on to neighbouring Louisiana with flood warnings in place for the Gulf Coast.