According to Jorhat district SP Amanjeet Kaur, the bus was carrying 70 passengers from Barpeta to Tinsukia against its capacity of 35 persons.
"The accident took place around 2:30 AM on NH-37 at Koliapani under Teok police station. Preliminary investigation suggests that it is a case of over speeding and over-loading, because of which the driver lost control," she said.
All the passengers have suffered injuries and they have been admitted to Jorhat Medical College and Hospital.
The condition of 10 persons is stated to be critical, Kaur said.
Yesterday, nine persons, including five women, were killed and 28 others injured when a bus fell into a ditch at Uluani in Nagaon district.
Assam Chief Minister Tarun Gogoi has ordered an enquiry into the accident by the Secretary of Transport Department.