The protestors threw stones at the district magistrate Harihar Prasad and police superintendent Aunsuiya Ransingh Sahu when they came to remove protestors shouting slogans in favour of RJD on Jay Prakash Narayan overbridge in the district.
Deputy Inspector General of Police Ajit Kumar Rai confirmed incident and said an FIR has been registered in this connection.
The police chased away the protestors and restored traffic on the overbridge, which connects Sonepur with Patna district, sub-divisional officer Sudhir Kumar said.
Reports of road blockade and protest march by RJD supporters also poured in from Hajipur and Begusarai among others during the day.
The RJD supporters held protests against Kumar and also against the denial of a chance to RJD, the single largest party in the house to form the government.