Police in Rockford, Illinois, were on the scene Thursday investigating an active shooter situation at an extended stay hotel.
"Please avoid the area," police said on Twitter.
Numerous police vehicles descended on the Extended Stay America, and police said they would release more information within an hour.
Multiple local media outlets reported that an officer assigned to the U.S. Marshal's Service was shot. The condition of the wounded officer was not immediately clear.
Extended Stay America has more than 600 locations across the nation. The suites, which include kitchens, are booked by the day, week or month.
Rockford is about 90 miles northwest of Chicago.