Two women, a 9-month old boy and two men died in the tragedy while many were injured.
Injured passengers said that the driver had been asked to take some rest after he was caught napping.
Driver had been handling a container with gasoline aboard the vehicle when bus caught fire.
Reports from Chamoli district said the injured are undergoing treatment at the District Hospital in Gopehswar.
Roadways bus carrying 52 passengers was going from Delhi to Guptkashi when the mishap occurred at Saknidhar.
The bus driver, identified as Kumar, has been arrested by the Indiranagar traffic police.
Seventeen persons were killed and twelve seriously injured when a bus fell 400 mts deep into a gorge near village Milla.
While most passengers suffered minor injuries, a few of them were referred to PGI and are said to be critical.
The 55-seat vehicle had 61 people on board when it overturned, and among the passengers, 12 were minors, police said.
Two buses collided at Partap Chowk flyover on Thursday injuring 12 passengers who were rushed to various city hospitals.
Police and rescue teams kicked off rescue operations and retrieved the dead and injured.
Sixteen critically injured persons have been shifted to zonal hospital in Dhangadhi.
Around 12 passengers suffered injuries and were taken to GMCH-32.
Locals rushed to the spot and rescued the injured.
The rescue teams faced problems in taking the bodies out of the wreckage of the bus.