The firing took place after a group of about 15 women entered the office of the block development officer (BDO) Braj Kishore Ram and started protesting against dearth of relief.
The BDO asked his security personnel to remove the women from his office. At this, the security men pushed out the women and some of them fell down.
This enraged the male demonstrators, most of them from Seema Mushahri village in the district, who then started pelting stones at the office, the police said.
Three persons suffered slight injuries in the melee, he said.
Later he and the Darbhanga District Magistrate visited the spot where the situation was now under control, the SP said.
Sub-divisional Officer (SDO) Gajendra Prasad Singh and others are camping there, the police added.