Nine children were admitted to a nearby medical facility for treatment where condition of two is said to be serious.
The victims included the van driver. The vehicle belonged to the Tender Heart school.
The incident took place at an unmanned crossing at Kairmau on the Varanasi-Allahabad rail section, an official told IANS.
In its preliminary probe, railway officials have found that despite being alerted by the ‘gang man’ that a train was on way, the driver overlooked it and drove ahead.
There were a total of 19 children in the van.