The protesters shouted slogans against Kumar demanding regularisation of service and parity in salaries and allowances with the permanent primary school teachers.
They were later evicted by JD(U) workers who had turned up in large numbers at the chief minister's public meeting.
Official sources said independent MLA Sanjeev Shyam Singh was put under house arrest to prevent him from joining the protest and videographers were deployed at his house to monitor his activities.
Addressing the gathering, Kumar attacked RJD chief Lalu Prasad and Rabri Devi for being 'unable to digest the success of the NDA government.'
Kumar renewed his demand for special status to the state saying that it was necessary to lift the state to the national average of development.
On the demand by protesting contractual teachers for pay hike, he said the state government would consider it had it more funds and urged the protesters to join his 'crusade' for special status to Bihar.