Five children were injured after the pool car ferrying them to school climbed on the median divider in Thakurpukur and turned on its side on Thursday morning.
The children suffered minor injuries, police said.
The accident happened around 6.20am near the Thakurpukur railway crossing.
"The driver of the Tata Sumo, which was taking the five children to Mothers Mission School in Behala, tried to avoid a concrete slab and ended up climbing the median divider. The vehicle moved for about 20m with the wheels on one side on the divider. The driver said the car fell on its side when he tried to get it back on the road," said an officer of the Thakurpukur traffic guard.
The driver has been arrested on charges of rash and negligent driving.
The officers called the parents of the children and informed them about the accident.
"Of the five children, one is in kindergarten, two in Class I and one each in Classes IV and V. They were handed to their parents," said an officer of the traffic guard.
The car was supposed to pick up another six students on its way to school.
From Kabardanga, the car heads towards Behala, a parent said.
The police also called the parents of the other children who were waiting for the car to inform them about the accident.
The students enter the school at 7am and classes start at 7.30am, a school official said.
Rounak Barkandaj, a Class V student who was in the car, told his mother that his legs were shaking when he was taken out of the vehicle.
"He was sitting on the rear seat of the Tata Sumo and fell on another student. Rounak said his legs were shaking while he was being taken out of the vehicle," said mother Sweety Rozario.
Rounak and another child had boarded the car from Kabardanga at 6am.
"I got worried after seeing the turned vehicle lying on the road on its side. But thankfully the children were standing on the footpath and were safe," said Rozario.
Another parent, Uttam Naskar, said he had received a call around 6.30am about the accident. His son is in Class IV.
"My son did not complain of any pain, but he was in a state of shock," said Naskar.