Four people, including two children, were hurt in a collision between a bus and an SUV at  Lower Wacker and Columbus drives, fire officials said.

The accident occurred about 8 a.m.

It was unclear what type of bus was involved, but a CTA spokeswoman said the agency had received no notice of an accident involving one of its buses.

The injured were taken to Northwestern Memorial Hospital, fire officials said. One of the adults was in serious-to-critical condition.

Chicago police had no immediate information.