Nearly 80 tornadoes battered the region as of 8 pm local time (0200 GMT, Monday), most of which took place in Illinois and Indiana, with a few in Kentucky, the US National Weather Service said.
Extensive damage was reported in the towns of Washington and Pekin in northern Illinois, where parts of the town have been leveled and many buildings destroyed.
Storms darkened downtown Chicago at midday, bringing heavy rains and strong winds, the speed of which could reach as high as 70 mph. Witnesses even spotted funnel cloud in McHenry County, about 50 miles (80 km) northwest of Chicago.
Due to the storms, the Chicago Bears-Baltimore Ravens football game, scheduled to take place at noon at the Soldier Field in downtown Chicago, has been postponed, and the fans were evacuated to take shelter inside the Soldier Field.
The tornado danger continues to shift eastward across the lower Great Lakes and Ohio Valley.
The US National Weather Service warned that numerous powerful, fast-moving thunderstorms, capable of producing tornadoes along with widespread damaging winds and large hail, will continue to threaten the Ohio Valley and Mid-South Sunday evening.
Reports said that severe weather has wreaked havoc across 26 states in the United States on Sunday.