INDIANAPOLIS (AP) _ An airline spokesman says pilots lowered the altitude of a United Airlines flight headed to Chicago before diverting the plane to Indianapolis after an issue with the pressurization system.

The flight left Charlotte, North Carolina, around 6:50 a.m. Eastern time Sunday and landed in Indianapolis around 8:30 a.m. The Chicago Tribune reports a few passengers were examined by medical personnel but no one was taken to the hospital.

ExpressJet Airlines spokesman Jarek Beem says pilots found a mechanical issue with the plane's cabin pressure during the flight. He told The Indianapolis Star that the plane went from an altitude of 32,000 feet to about 10,000 feet in a controlled descent.

ExpressJet operated the flight, and is a regional partner of United.