Some people of the community took out a march to Dargah Hazrat Abbas last night protesting against the killing of Shias by militants in Iraq, police said.
However, they were attacked with bricks by some unidentified persons and three persons were injured in the incident.
"People came out of bylanes and were proceeding towards Dargah Hazrat Abbas when some mischievous elements targeted them near Ghanta Beg Gadariya resulting in minor injuries to three," said Amrendra Sengar, Inspector General of Police (Law and Order).
Sengar said three companies of PAC have been deployed and a demand for RAF has also been made.
"Senior officials are keeping a close watch on the situation there," he added.
The old city areas have a mixed population of Shias and Sunnis.