The deceased, who were cousins, have been identified as Aman Kumar (5) and Ritika (9), police said here.
The duo were residents of Khere Ke Uthar village in Jalalabad sub-division of Fazilka district.
The incident took place when the bus of Sacred Heart Convent School in Jalalabad was carrying the students back home and the driver lost control over the vehicle, as a result of which it overturned, police said.
At that time, 20-25 school students were in the bus. People from nearby places came to rescue the children.