The incident occurred near Toliyasar village in Sridungargarh area when the private bus was on its way to Bikaner from Sardarshahar in Rajasthan, they said.
Eight persons were killed and 25 injured in the collision, they said.
15 injured are being treated in a hospital in Sridungargarh, while 10 persons who were critically injured have been admitted to PBM government hospital, they said.
Senior police officers have rushed to the spot, they added.