The accused were racing on the western express highway near suburban Goregoan in wee hours yesterday, a police official said.
When the officials from Vanrai police station reached the spot, some of the youths escaped leaving behind their vehicles, police said.
Subsequently, police seized the bikes. During this time, few other motorcycle-borne youths pelted stones at the cops, they said.
While no police personnel sustained injuries, a combat vehicle was damaged, police said, adding 11 bikes were seized in total.
Police chased bikers and apprehended seven youths, they said, adding that investigations are underway.