However, Director-General of Police Khagen Sarma was hopeful that the missing passengers may have swum to safety.
"Most of the people in the area know how to swim, they probably swam across the river to the other side of the river bank," Sarma said. The boat has been fished out from the water, he said.
District administration sources said the search was being conducted by personnel of the National Disaster Response Force and State Disaster Response Force.
"No death of any passenger of the capsized boat has been reported to the police so far. So, we have presumed that there is no death in the accident," Sarma told reporters here.
The overcrowded boat was carrying about 200 people from Koraibeel to Gumi. The boat's engine had stopped midway and it hit a pillar of a bridge and overturned in Chaygaon area.
The passengers in the boat were travelling to witness a boat race nearby, the sources said.