An express train collided with the bus at an unmanned level crossing in Patiyali, 250km (160 miles) south of the capital, Delhi.
The bus was returning after a wedding when the accident happened.
A local journalist said the train dragged the bus full of passengers up to 500 metres down the track.
The accident happened at about 0200 (2030 GMT Wednesday).
People sitting on the roof were thrown off and seriously injured while those inside the bus were crushed.
Many of the injured have been admitted to hospital while efforts are continuing to free those trapped in the wreckage.
One of the injured told a local journalist that he had been sitting on the roof of the bus when he saw the train coming towards them.
He said he'd warned the driver, but he did not appear to hear him..
The bus was returning after a wedding when the accident happened.
A local journalist said the train dragged the bus full of passengers up to 500 metres down the track.
The accident happened at about 0200 (2030 GMT Wednesday).
People sitting on the roof were thrown off and seriously injured while those inside the bus were crushed.
Many of the injured have been admitted to hospital while efforts are continuing to free those trapped in the wreckage.
One of the injured told a local journalist that he had been sitting on the roof of the bus when he saw the train coming towards them.
He said he'd warned the driver, but he did not appear to hear him..
