A bus that ferried students of MP Birla Foundation Higher Secondary School was gutted on Tuesday afternoon.

There was on one on the bus when the fire broke out, police said.

Findings of a preliminary investigation suggest an open fire in a roadside kitchen near Douglas Ground off Diamond Harbour Road, close to which the bus had been parked, led to the blaze.

The bus, belonging to a private operator, was parked about 2km from the school when it caught fire around 1.20pm.

Two fire engines were used to douse the flames, the police said.

“The bus had a GPS installed apart from a fire extinguisher, a CCTV camera and a first-aid box. Everything has been damaged,” a school official said.

The bus will undergo forensic tests to ascertain the cause of the fire, an officer of Thakurpukur police station said. “The seats were stuffed with foam. They caught fire and the flames spread inside the vehicle. Thankfully, there was no one inside,” the officer said.

Students who were to travel on the bus were sent back home on another bus.

The bus owner produced all vehicle papers. “Till now, we have not found anything suspicious,” an officer said.