Members of NIMA, including ayurvedic and unani doctors, staged a dharna in front of Vidhan Bhawan here demanding amendment to the Act, so that could use modern allopathic medicines.
Trouble broke out when the protesters attempted to move towards Vidhan Bhawan where budgets of various departments were being tabled, police said.
Police initially tried to stop the protesters, but when they forced their way and blocked the road, they used force to control them.
More than six persons, including a senior sub inspector Dinesh Singh, were injured in the clash.