Chicago, May 2 : A dust storm caused pileups from vehicle crashes on a highway in US Midwest state of Illinois, according to local authorities. More than 30 people have been sent to hospital for injuries, and the number of fatalities has not been confirmed, Xinhua news agency reported. State police troopers responded to numerous crashes about 11 a.m. Monday on both directions of I-55 in Montgomery County, south of Springfield, capital of Illinois, the Chicago Tribune quoted the police as saying on Monday. About 20 commercial motor vehicles and 40 to 60 passenger cars were involved in the crashes, including two tractor-trailers that caught fire. The crashes were caused by "excessive winds blowing dirt from farm fields across the highway leading to zero visibility," police said. I-55 is currently shut down in both directions. State police are investigating. /IANS