Anger mounts over Texas power blackouts as cold maintains its grip

At least 20 people have died across the country as water pipes burst and lines wrap around grocery stores

Anger over Texas's power grid failing in the face of a record winter freeze is mounting, as millions of residents remained shivering, with no assurances that their electricity and heat - out for 36 hours or longer in many homes - would return.

I know people are angry and frustrated," said Houston's mayor, Sylvester Turner, who woke up to more than 1 million people still without power in his city on Wednesday. So am I."