The driver of the van carrying the children to school lost control over the vehicle and hit the truck, police said.
Bodies of Ruchika (6) and Shalu (7) who died on the spot, were sent for post-mortem, SP, Ramesh Chandra Sahu said.
Karan (4), Prithviraj (6) and Neha (7) injured in the mishap have been admitted to a hospital, the SP said.
Infuriated over the accident, locals blocked the road and raised slogans against the administration, Sahu added.