Lucknow: A school bus carrying more than 50 children collided with a sand loaded truck resulting in at least 24 children deaths, here at Lucknow , as reported by the local police officials.
At least two dozen other children were injured when the speeding truck collided head-on with the bus, said Javeed Ahmed, the state's police official.
The children, between the ages of 3 and 12, were studying at a school in the town of Etah.
Another police officer, Daljeet Chaudhry, said visibility was low due to dense fog.
Police officer Parasuram Singh said the truck driver suffered serious injuries to his legs, which were amputated at a hospital.
The area is about 270 kilometres (170 miles) southeast of New Delhi.
State education authorities had already closed all schools in the district because of a severe cold wave, and Ahmed said authorities would check why the school had stayed open.
Prime Minister Narendra Modi tweeted his condolences, saying: "Anguished by tragic accident in UP's Etah. I share the pain of the bereaved families & condole (the) passing away of young children."
Accidents are common on Indian roads, with most blamed on reckless driving, poorly maintained roads and aging vehicles.