Several schools that stayed open during Wednesday’s BJP-called bandh because the state government had ordered them to said on Thursday that they were jittery about doing the same next time after what happened to a DPS Megacity bus carrying students.

Education minister Partha Chatterjee had promised protection to schools that defied the bandh and threatened action against those who had suspended classes and postponed examinations.

But there was none to rescue a group of students and teachers in a DPS Megacity school bus that was waylaid and attacked by bandh supporters near BT College More on Jessore Road around 7.10am.

Several of the children who saw the violence are still traumatised by the experience, their parents said.

The debate on campuses was whether keeping children safe was a more prudent option than sending out a strong message by defying a bandh. The overwhelming opinion was that schools could not afford to put their students at risk.

“We are answerable to the parents and nobody else. If a bus gets stuck on the way, it is now evident that there will be nobody around to protect the students,” said an official of one of the city’s newer schools.

Officers in the Bidhannagar police commissionerate — the attack on the DPS Megacity bus occurred under the jurisdiction of Airport police station — said there was “no special instruction from the government to take additional measures for the safety of school buses”.

The security arrangements on Wednesday were like those for any other general strike or bandh, an officer said.

The police apparently did not even draw up a list of schools that would be open during the 12-hour bandh. Schools were not approached or advised to intimate their local police stations about the routes of their buses.

Teachers and students in DPS Megacity bus did not see any police patrol during the time they were held hostage by bandh supporters.

On the eve of the BJP bandh, the education minister had said that schools had little to fear and should not make any excuses for suspending classes. “I had repeatedly made it clear over the past three days that each and every educational institution, government-aided and private, should function as usual and there should not be any disruption on Wednesday,” Chatterjee told Metro.

He separately told the TV channel ABP Ananda: “The security of students is the government’s responsibility.”

Chatterjee threatened to review and “even cancel” the no-objection certificates issued by the government to schools that ignore the appeal to stay open during the bandh.

The education minister and school education secretary Manish Jain did not take calls from Metro.

Bidhannagar police said the incident at BT College More, where the portion of the airport boundary wall facing Jessore Road ends, was the handiwork of a handful of BJP supporters and lasted around 20 minutes. “Our patrol had just gone past the area when the blockade started. So they missed it,” a senior officer said.

A police team arrived after the school bus left with its windshield broken. The bandh supporters were asked to disperse but nobody was arrested.

An officer said four patrol vehicles had been deployed in the areas under Airport police station and that they had been told to “keep a close watch on Jessore Road”.

On Thursday, the police provided a pilot car to escort two DPS Megacity buses through the area on their way to and back from the school’s Rajarhat campus.