A large explosion rocked a shopping plaza in the Chicago suburb of Waukegan, Ill., on Thursday, injuring at least eight people and rattling nearby buildings, authorities said.

The explosion struck the shopping centre about 70 kilometres from Chicago around lunchtime Thursday. The blast blew the windows out of storefronts and collapsed the ceilings above stores.

Five people were taken to hospital, none with life-threatening injuries, and another three were treated at the scene, Deputy Fire Chief Dan Young said.

The injuries included smoke inhalation and bumps and bruises, he said.

Authorities said the cause appeared to be a gas explosion. Crews from Peoples Gas were on the scene to investigate.

Candi Rixie said she was taking orders at a sandwich shop a block away when she heard a boom.

"We felt like an earthquake, like somebody had hit the building with a car," she said.