A teen has been freed from the wreckage of a horror crash after a stolen unmarked police car hit a bus in Melbourne's east.

The crash occurred as police attempted to intercept the stolen car in Box Hill, shortly before 1pm on Friday.

Another unmarked police car spotted the stolen vehicle, carrying two males believed to be aged in their teens, on Asquith Street travelling west towards Station Street.

A police officer in a third unmarked police car pulled into the end of the street, got out of the vehicle and attempted to wave down the stolen car.