Investigators say three unmarked police vehicles, with their lights and sirens on, were traveling ahead of the motorcade on the West Side. One of those police vehicles struck a taxi that had gone around traffic stopped because of the motorcade.
A passenger in the livery cab refused medical attention at the scene. The cab driver and two police officers were examined at a hospital and were released.
The advance team drives the motorcade route several minutes before the motorcade itself. Vice President Joe Biden was visiting the city for a television appearance.
Secret Service spokesman Darrin Blackford said the motorcade continued on its route to the Comedy Central channel show's studio, a few blocks from the accident site.
Biden was told about the accident after taping the show. He spoke with one of the injured officers and the officers' supervisor from his plane on the way back to Washington, D.C., his spokeswoman Elizabeth Alexander said.
"He was very happy to hear reports that the injuries were not serious and that all involved have already been released from the hospital," Alexander said.
In another accident involving the vice president this week, a sheriff's deputy was injured Monday in Albuquerque, N.M., when a woman drove around police vehicles blocking an intersection and collided with the deputy's car.
Biden had been in Albuquerque to speak at a campaign fundraise for two New Mexico Democrats.