A slipper was flung towards chief minister Nitish Kumar by some protestors while he was going towards his helicopter after completing speech at an election meeting in Sakra in Muzaffarpur district, but it missed the target.
Police took four persons in custody on the charge of creating disturbances at the chief minister's rally, police sources said.
The Sakra incident is in the series of protests Kumar is facing during his rallies in different parts of the state.
At many places, Kumar lost his cool and chided the protestors for "acting on behalf of political rivals" and telling them that nobody is bothered even if they don't vote for him.
Addressing rallies in Sakra and Mahua, Kumar hit out at the Rashtriya Janata Dal for making "fake" promises during polls to "cheat" the people.
Kumar has been deriding opposition chief ministerial candidate Tejashwi Yadav's promise of providing 10 lakh jobs if voted to power.
Kumar addressed rallies at Sakra and Kanti in Muzaffarpur district then he moved to neighbouring Vaishali district where he spoke at public meetings in Mahua and Mahnar assembly seats.
Mahua constituency is in the news because Lalu Prasad's elder son Tej Pratap Yadav, who represented it in the outgoing assembly, has relinquished it and moved to Hasanpur constituency in Samastipur district.
Mahnar too is in the media headlines because it includes the native place of veteran socialist leader Raghuvansh Prasad Singh, who had quit RJD before his death last month.
His son Satya Prakash Singh has joined Janata Dal-United headed by Nitish Kumar.
"Some leaders are making lofty promises before polls to cheat people, they have no genuine interest in work, whereas we have translated all our promises into reality," Kumar said taking a swipe at Lalu Prasad's headed party while speaking at Mahua.
Kumar said while the RJD cared for one family (of Prasad) and some caste and community but our successive governments have worked for promoting interests of all caste and creed.
Like in the earlier rallies, Kumar reeled out data to underscore developmental records of the RJD during its 15-year rule and that of the NDA ministries for an equal duration after 2005.
"For some family means wife, sons and daughters for me Bihar is the family for whom we work tirelessly," the chief minister said, taking a jibe at his bete noire RJD supremo Lalu Prasad.
He highlighted development work done in the last five years by executing "saat nishchay" (seven resolves) of good governance and promised to carry forward the work by implementing seond part of the seven resolves which will include providing irrigation to every farm land.
Accompanied by state minister Sanjay Kumar Jha, the chief minister reminded people of the "jungle raj" prevailing in the state during the RJD regime when crime was rampant and asserted how his government ended it and established "rule of law."