Eleven people were hospitalized after a car fleeing from gunmen smashed into a bus in Chicago city Tuesday, the Chicago Tribune said.

A witness said that two men jumped from a red truck around 9:30 a.m. and started opening fire at a black Intrepid sedan, as the truck followed them.

The car smashed into a bus, as it fled down the street, pushing the bus into a light pole, another witness said.

It appeared that no one was hurt by gunfire, but instead were injured in the accident or by flying glass, according to officials and witnesses.

The gunmen fled in the truck after the shooting.

Lambrini Lukidis, a spokeswoman for the bus firm, confirmed that the bus driver and four passengers were injured, but their injuries were not believed to be life-threatening.

A witness said he saw at least five others who were hurt in the accident, including one in the car, three on the sidewalk and a woman who has been getting ready to park.

A Chicago Fire Department spokesman said two people have been transported to hospital in serious-to-critical conditions, while other nine people were taken to different hospitals in fair or good condition. Three people declined treatment from paramedics on the scene.