Jagdish Mehta, Headmaster of Dak Haripur Kanya Madhya Vidyalaya in Forebesganj, has been put under suspension, District Education Officer Faizul Rahman told PTI.
Probe into the incident was on, he said.
The incident took place on March 18 when a group of BJP workers hoisted a party flag in the school premises to celebrate BJP's victory in UP.
When the incident drew wide media attention, the District Education Officer on March 23 directed the Block Education Officer concerned to investigate the matter.
Those party workers did not find a suitable place to hoist the flag to celebrate the win and did it in the school, Singh had said.