At least 15 people were killed and 25 others injured when a minibus in which they were travelling overturned and fell into a pond at Dewanhat in Coochbehar district on Sunday.
Fifteen bodies were brought out from the submerged bus and taken to the morgues in MJN Hospital and Dinhata Sub-Divisional Hospital for postmortem, the police said.
The vehicle was later hauled up from water with the help of a crane as fire brigade, disaster management and police personnel joined rescue work along with locals.
The police resorted to mild lathicharge to disperse a mob, which damaged a police van near the block hospital at Dewanhat to protest the alleged delay in treating the injured.
Locals alleged tear gas shells were also burst but this was denied by authorities.
Four of the 25 injured had to be shifted to MJN Hospital.
The dead included a schoolgirl Shweta Roy, studying in Class IX, who was going to Dinhata to visit relatives, locals claimed.
Eyewitnesses said the mishap occurred as one of the front tyres of the minibus, travelling from Coochbehar town to Dinhata, suddenly burst.
Traffic movement along Dinhata-Coochbehar highway was stalled for several hours as locals blocked the arterial road to protest "rash driving".