A bus carrying 70 children and two teachers of Mandoli- based Saraswati School was travelling at a very slow speed on the Dadri-Mahendragarh road this morning because of dense fog when a speeding truck coming the opposite direction collided with it, they added.
The impact of the collision left 18 children and two teachers injured, police said, adding that they were rushed to a nearby hospital.
Five-year-old Aarush was declared "dead on arrival" by doctors at the Rohtak PGI hospital and the four others were undergoing treatment, they added.
The body of Aarush was handed over to his family after postmortem, police officials said.
Dadri Deputy Superintendent of Police Pradip Kumar later said the truck driver fled from the spot after the accident, adding that a case was registered against him and investigation was underway.