Police on Monday said they had registered a case of rioting against supporters of spiritual guru Asaram Bapu who attacked police personnel overnight here, injuring seven policemen.According to police, the police personnel were injured when some 2,000 people demanding Asaram Bapu's release stoned the Parliament Street police station in the heart of the city on Sunday night.A few police vehicles were also damaged in the protest. No arrests have been made yet, a police officer told IANS.Asaram Bapu, lodged in Jodhpur Jail in Rajasthan after his arrest in 2013, has been accused of sexually assaulting a 16-year-old girl. He has denied the charge.