Massive Christmas winter storm arrives in US Midwest
More than 260 flights from Chicago have been cancelled
A "humongous" winter storm is spreading across the US Midwest, forecasters say, already affecting holiday travel and cutting power to hundreds of homes.
The worst of the storm is expected to hit late on Thursday and dump up to 2ft (61 cm) of snow by Christmas Day.
Icy roads were blamed for the deaths of six motorists in Nebraska, Kansas and New Mexico, while more than 260 flights from Chicago's airport were cancelled.
The US East Coast is still recovering from a record snowfall last weekend.
Tens of thousands of customers in West Virginia and Virginia are still without power.
ANALYSIS
From the BBC Weather Centre
The storm system developed across western parts of the US producing dust storms across the desert areas of California and Arizona.
The same system is now currently across the Midwest and is generating severe blizzards from Kansas to Minnesota.
As the system pushes eastwards forecasters expect an ice storm to affect large parts of the interior of the north-east US during Christmas Day and Boxing Day.
Although the storm is severe, winter storms are not uncommon in the USA during the winter months.
The latest storm began in the south-west on Tuesday, causing blizzard-like conditions and travel chaos, before spreading to the east and north.
"There's just a humongous storm moving across the centre of the country, basically from the Canadian border to Texas and spreading from west Colorado to Illinois," Pat Slattery, a spokesman for the National Weather Service, told AFP news agency.
"We would recommend that people if at all possible postpone their travel plans just to be on the safe side," he said. "This is not a storm to be messed with."
The biggest accumulations of snow were expected from eastern Nebraska to the Upper Mississippi Valley. Freezing rain was possible across parts of Kansas, Nebraska, Iowa, Illinois and Indiana, forecasters said.
South of the storm system, heavy thunderstorms will produce flooding across Texas and into the Ohio Valley, they warned.
More than 1,300 customers were without power in Iowa with temperatures hovering around freezing on Thursday, the Iowa Association of Electric Co-operatives said.
The governor of South Dakota issued a state of emergency even before the storm hit, and urged residents to stay off the roads until the storm passed.
