The collision happened on Chandigarh-Kharar-Ludhiana National Highway-95 at Mamupur village, some 6-km from Kharar, they said.
Two students and the school bus driver were killed and 53, including three students, injured in the accident, police said.
The dead were 15-year-old Mehakvir Singh, a class 10 student, Harpreet Singh (13), who was studying in class seven, and Harwinder Singh (40), the school bus driver.
At the time of the accident, five students were in the Kharar-based private school bus, police said.
Around 50 passengers were travelling in the private bus whose driver fled from the scene, police said.
