Polar vortex blamed for at least 8 deaths in US Midwest

At least eight people have been killed as a brutal cold spell swept across the United States.

Cities in the region have been forced to shut down as officials urged the public to stay indoors.

Known as a polar vortex, temperatures are set to drop to -30C in Chicago and -37C in North Dakota.

Forecasters say temperatures will drop to a record-breaking -17C or below.

More from International