Oklahoma officials remain worried that drivers stuck on highways could be trapped in the path of dangerous twisters spawned by the violent thunderstorms hitting the US state.
A mother and baby - who are among five confirmed killed by the latest tornado - died when their car was flipped on Interstate 40.
Between 40 to 50 people are being treated for storm-related injuries, health officials have said.
Five patients, including a child, are in critical condition.
More top news
Socialite Tara Palmer-Tomkinson has been cautioned by police after a 'disturbance' at Heathrow Airport.
The NHS is to set up 11 centres to unlock the secrets of DNA and help develop tests and drugs to target cancer and rare genetic diseases.
Australian businessman named as Alan Sugar's newest apprentice and winner of a £250,000 investment in his fledgling company.