Three buses were torched and several other vehicles damaged as the opposition Trinamool Congress-backed autorickshaw operators went on a rampage on Saturday at Park Circus in South Kolkata spreading panic among school children and commuters. A large contingent of police were present, but could do little as the auto operators, protesting against the ban by the Calcutta High Court on the polluting two-stroke three-wheelers from January 1, indulged in violence.