The dispute broke out between jail staff and inmates after some psychotropic substance was recovered during a routine checking this morning, police said.
As the situation went out of control, teargas shells were fired in the air and water cannons used to disperse the inmates who turned hostile and pelted stones, police said, adding nine policemen were injured including SP Prabhakar Chaudhary, ASP NK Singh and CO (City) Sushil Kumar Singh.
District Magistrate Anita Srivastava said the situation was under control and (Provincial Armed Constabulary) PAC was deployed.