Out of the nine held, three were named in the FIR lodged in connection with the clash that took place yesterday.
"All the nine have been booked under non-bailable sections of IPC and we are probing into the roles they had in the clash," an officer of Tangra police station said.
Five police personnel were injured in the clash in which bombs were hurled and five rounds of bullets fired. The policemen were injured when stones were thrown at them when they arrived at the spot to control the situation.