The protestors resorted to violence and threw stones at the police after their leader was taken into custody, district Superintendent of Police Babu Ram said.
Protestors have been agitating for the past one week at the venue of the power project being built jointly by NTPC and the state government at Nabinagar after some workers were sacked by a private construction company involved in the project.
A team of policemen station arrived at the site today and in a bid to quell agitation took their leader into custody. This irked the workers, who attacked the police and allegedly roughed up station house officer Aman Anand.
The SP and district magistrate Kawal Tanuj are camping at the venue, the police said.