Homeless encampment is set up INSIDE Chicago's O'Hare Airport

Homeless encampments have sprung up inside crime-riddled Chicago's O'Hare International Airport terminal leaving some concerned for their safety as images of people sleeping in filthy makeshift shelters have emerged.

Thousands of people sleeping rough have sought refuge at the popular airline hub, with many setting up shelters inside the terminal buildings.

Passengers were quick to snap the deteriorating situation with one Twitter user posting a photo of several people sleeping among a throng of belongings near Terminal 1 of the airport.

Other shocking photos show one man collapsed inside an entrance vestibule, another slumped over with no shoes on and a group of half a dozen people who have taken over an indoor area next to the escalators.