The accident occurred between Makan and Chakhumai area along the Imphal-Dimapur National Highway 39 at 3.30 am.
The bus was heading towards Imphal when it fell into the stream at the site, located about 65 km from the state capital, the officer said.
The cause of the accident was not immediately known.
The injured have been rushed to the nearby Assam Rifles Maram Hospital and other hospitals in the vicinity, the officer said.
The death toll is likely to rise as many of the injured are in serious condition, the officer added.
Source: The Tribune(PTI)