Police arrested three BJP workers on Tuesday evening for locking up teachers and non-teaching staff at their school building in Ashoknagar in North 24-Parganas as “punishment” for keeping the institution open on Janmashtami.

The BJP workers had locked the main gate of Ashoknagar Kalyangarh Sanskriti Sangha Sikshaniketan, a state-run school, “to teach the staff a lesson”, headmaster Prabir Kumar Saha alleged.

Based on his complaint, the police arrested BJP workers Parthapratim Chakraborty, Shyamal Mullick and Nilratan Mitra.

A local source said that on Tuesday the headmaster and some other staff opened the school despite the lockdown and Janmashtami holiday to discharge some urgent work. But, this angered the BJP workers, who, led by the party’s local convener Swapan Kumar De, allegedly barged inside the building and created a furore.

Saha said: “They threateningly asked me why I dared to open the school on Janmashtami. We tried to explain that we were compelled to open the school for a few hours only. They insisted we stop our work immediately, but we refused to oblige. To teach us a lesson, they left the campus and locked us in.”

Contacted, BJP leader Swapan Kumar De appeared unrepentant. “We advised the headmaster to keep the school closed today (Tuesday) because it was Janmashtami. We did nothing wrong as he misbehaved and refused to listen to us,” De said.