Severe winter storm puts much of US on high alert

Tens of millions of Americans are bracing for a huge winter storm that could bring the heaviest snowfall and coldest temperatures in over a decade.

The storm, which started in the middle of the US, will move east in the next couple of days, the National Weather Service (NWS) said.

A state of emergency has been declared in the states of Kentucky and Virginia, and parts of the US unaccustomed to severe cold, including Mississippi and Florida, have been warned to expect treacherous conditions.