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.
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As the silence came to an end the crowd began to applaud and people shouted "I am not afraid!" in defiance of the attacks.
Italian Bruno Gulotta, 35, and Belgian mother Elke Vanbockrijck have been confirmed among the dead after a van mowed through crowds.