Updated

Illinois State Police say snowy weather caused two crashes on a Chicago expressway that involved a total of 34 cars.

A State Police spokesman says seven people sustained minor injuries in Monday night's pileup on the Kennedy Expressway. Both wrecks occurred in the express lanes of the highway on the city's North Side.

Police say both crashes happened in the same area and the express lanes were closed for hours. Local lanes of the expressway remained open.

Additional details were not immediately available. Illinois State Police is investigating.

The National Weather Service issued a lake-effect snow warning for Chicago that expires Tuesday afternoon.