Nineteen other passengers too were injured in the fire in the vehicle on way from Bathinda to Ludhiana, police said.
SSP Naveen Singla said the injured had been taken to the civil hospital here where the condition of five of the passengers is "serious".
According to the eye witnesses, the bus caught fire from the rear end and the vehicle kept moving for another 300 meters till the flames reached inside the bus.
The doors of the air-conditioned bus got jammed and the toll could have been higher but for the locals who rushed to the aid of those trapped and rescued them by breaking the window panes, police said.
The dead were charred beyond recognition, police said.