A severe snowstorm in the US Midwest forced more than 90 flights to be cancelled at Chicago’s O’Hare airport.

The US Federal Aviation Administration said that flights into Chicago were being delayed at their place of departure. Some flights were being delayed by more than two hours.

Blizzard conditions and as much as 1ft of snow are expected from Kansas to Wisconsin, with the Rocky Mountains already affected.

At least four people are reported to have died in the storm which could see temperatures plunge below -17C.

The severe weather could disrupt pre-Christmas travel, officials warned.

Two people died in a car crash in Wisconsin, one was killed in a 25-vehicle crash in Iowa, and a woman died in Utah after becoming stuck in snow. Rescuers in Utah found a woman dead after she tried to walk to find help after her car became stuck in snow.

High winds are reported to have damaged homes and downed trees in Arkansas and Alabama while tornado warnings were in place yesterday for parts of Mississippi, Louisiana and Alabama.