The incident occurred at Eturunagaram here ahead of Srihari's visit, who was supposed to attend the governing body meeting of the Integrated Tribal Development Agency.
Anticipating trouble, circle inspector Kishore Kumar asked police personnel to disperse the workers, who in turn lathi charged them.
However, police officials present on the spot did not elaborate on the exact provocation that led to the incident.
Many workers suffered injuries even as police detained 100 of them before releasing them in evening.