The deceased were identified as Jamnadas (57), Viond (32), Rajpal (22) and five-month-old Khushbu, all hailing from neighbouring Uttar Pradesh.
Five seriously injured passengers were referred to a government hospital in Chittorgarh, police said, adding 19 others were discharged after first-aid.
The driver of the bus, which was on its way from Rajkot to Kanpur, fled the scene after the accident.
Police said the exact reason of the mishap was yet to be ascertained, but suspected that the driver might have dozed off while on wheels.