Shimla: Seven passengers were killed and 11 others injured when a private bus overturned and plunged onto a lower road in Chamba district at 7:15 am on Saturday, police said. SP Chamba, Vijay Saklani, told PTI that the exact number of people on the bus is not yet known. Of the 11 injured, six with serious injuries have been referred to Pt Jawaharlal Nehru Government Medical College and Hospital, Chamba. Police said the death toll can rise further as passengers could be buried under the wreckage of the bus. So far, 78 people have died in road accidents in Himachal Pradesh during the ongoing monsoon season from June 30 till August 7, police said.