The incident happened near Bjaiya village.
Charkha Patthar Station House Officer (SHO) Deepak Kumar said the deceased have been identified as Parvati Kumari (12) and Hasnain (02).
"The children were playing on the roadside when the speeding truck ran over them. Both were killed on the spot," the SHO said.
The police officer said the truck was on its way to Sono after unloading stone-chips at Bijaiya village.
"Villagers ran and tried to stop the vehicle after the accident, but it escaped injuring four persons, including three women," Kumar added.