The condition of two of the passengers was stated to be critical.
The bus, carrying about 40 tourists from the southern state, was on its way from Shimla to Manali when the mishap occurred at a spot around 25 kms from here.
Those seriously injured were rushed to the IGMC hospital here, while the other injured persons were admitted to a hospital at Dhami.
Chief Minister Virbhadra Singh visited the injured tourists at the Dhami hospital and said all of them would be shifted to IGMC where they will be given free treatment.