Residents of Bhagwat Nagar and Jaiprakash Nagar colonies, who were opposing the drive that was being carried out on a Supreme Court directive, set on fire a government car when the demolition squad arrived, the police said.
They also burnt tyres on the road to prevent entry of the demolition squad.
The womenfolk too joined the protest and sat on a dharna, besides blocking entry of vehicles in the two colonies, they said.
Additional District Magistrate (ADM) Ramesh Kumar was camping on the spot with additional police force to bring the law and order situation under control, the police said.
The Supreme Court, in its September 8 order last year, had directed the Patna Municipal Corporation (PMC) to demolish illegal constructions in the two colonies by September 26 next.
The apex court had directed the PMC to hand over the land to the Bihar Finance Co-operative House Construction Society, after which the authorities had identified about 131 illegal houses for demolition today, the police said.
