Three or four incidents of stone-pelting were reported.
A group, after returning from Friday noon prayers from Mecca Masjid, pelted stones which injured three policemen and smashed window panes of two police vehicles under Moghalpura police station limits, a senior officer said.
Police fired two rounds of tear gas shells to disperse the protesters, Assistant Commissioner of Police S Gangadhar, who was among the injured, said.
Viquar Ahmed alias Ali Khan, founder of the militant group Tehreek-Ghalba-e-Islam, and his four associates were killed after police fired in "self defence" as they allegedly tried to escape from a police van near Tangutur in Nalgonda district three days ago.
Two police personnel had suffered injuries after a mob returning from Viquar's funeral on Wednesday night pelted stones. They also tried to torch a police bus, besides damaging a police vehicle and a bike, Kumar said.
A heavy police bandobast was maintained in the Old City today with deployment of Rapid Action Force. Police Commissioner M Mahender Reddy supervised the security arrangements.