A man was taken to hospital with a gunshot wound after a police car was flagged down in Birmingham city centre.
Officers were stopped in Bristol Street just after 05:30 GMT, West Midlands Police said.
"The 24-year-old was in a white Audi and his injuries are not believed to be life-threatening," a spokeswoman added.
Two vehicles and several other men are thought to have fled the scene. Anyone with information was asked to contact police.