Two boys who were questioned after a police officer was injured when several shots were fired have been released.
Officers were speaking to a motorist at the junction of Leytonstone High Road and Wingfield Road, east London, just after 0000 GMT on Saturday.
A female officer, who was inside a police vehicle which was shot at by a passing car, suffered slight grazing.
Scotland Yard said the 17-year-old boys who had been arrested had been released with no futher action.
The officers involved in the shooting received treatment at hospital, but were later discharged.
Shortly after the incident the Saab estate car that was involved was seen in the area and was followed by police.
The vehicle was abandoned at the junction of Idmiston Road and Globe Road where it was set alight before a number of occupants ran off.