The Himachal Road Transport Corporation (HRTC) bus was on its way from Chamba to Kinnaur when it crashed in the remote Panji tribal area near Churah Nulla, police said.
Five of the injured are said to be critical and are referred to regional hospital Chamba, police said.
Four other are sent to a local hospital in Baragarh, 900-kms from Chamba.
Deputy Commissioner Chamba M Sadha Devi said, "Rescue work is in progress. More details are awaited.