At least six people have died and dozens more have been injured after a dust storm caused a large pileup on a highway in Illinois, police said late on Monday.

The incident involved around 40 to 60 passenger cars and several big-rig trucks on Interstate 55 (I-55) near Springfield.

More than 30 people were taken to hospital with injuries.

"The cause of the crashes is due to excessive winds blowing dirt from farm fields across the highway, leading to zero visibility," Illinois State Police Maj. Ryan Starrick said at a news conference.

Farmers are currently busy planting fields across Illinois and the Midwest, and wild winds have been known to blow topsoil away in the past.

Authorities describe 'horrific' accident

Starrick said the dust storm was the spring equivalent of a winter "whiteout situation" while Illinois Governor J.B. Prizker called the incident "horrific."

Two large trucks caught up in the crash caught fire and it is possible that one of them exploded, authorities said.

Kevin Schott, director of emergency services in Montgomery County, said this kind of accident is "very hard to train for."

"We had to search every vehicle, whether they were involved in the accident or just pulled over, to check for injuries," he said.

Highway closed

The affected section of the I-55 in Montgomery County was shut down in both directions after the crash.

"Visibility in the area is reported to be low due to blowing dust," Illinois State Police said in a statement.

"Traffic is urged to seek alternate routes. This investigation is in its infancy and there is no further information at this time."

US Representative Nikki Budzinski of Illinois said: "My team and I are closely following the devastating crash on I-55 as authorities learn more. Please be safe as this situation continues to unfold".