A tent collapse in suburban Chicago injured at least 26 people, police in the US have said.

Five of those hurt had serious injuries, Bedford Park police chief Tom Hansen said.

The tent collapsed at around 10.45am local time in the car park of a business, Mr Hansen told local news outlets.

The tent was being used for an event being hosted in the car park, he said.

“The Bedford Park Fire Department, along with multiple fire department agencies from surrounding jurisdictions, transported 26 patients to area hospitals for treatment,” police said in a news release.

Police said the cause of the collapse was under investigation.

Photos from the scene showed the large tent partially collapsed and partially still standing next to many tables set up with chairs.

The car park was outside a Cintas Uniform Services store in Bedford Park, about 15 miles south-west of Chicago.

Cintas issued a statement saying several employees were injured during the incident at an employee appreciation event.

“We are co-operating with local officials to determine the cause of the incident. Cintas will continue to monitor the situation and do everything we can to assist our employee-partners during this time,” the statement said.