The bus has been heavily damaged in the accident. Meanwhile, rescue operations are currently underway and the death toll is feared to rise.
According to officials, at least 40 students were in the bus when the accident took place.
Kullu Deputy Commissioner (DC) Ashutosh Garg said the bus, headed to Sainj, fell into the gorge near Jangla village around 8:30 am. District officials and rescue teams have reached the spot, he said, adding that the injured were being rushed to a nearby hospital.