The deaths in a boat capsize in the Hooghly river in West Bengal's Burdwan district rose to 18 on Monday, an official said.
An overcrowded boat capsized late Saturday night near Kalna Ghat in Burdwan while on way to Shantipur in Nadia district.
"Till now 18 bodies have been recovered," Burdwan district magistrate Saumitra Mohan said.
Nadia district magistrate Vijay Bharti on Sunday said at least 12 people were reported missing.
Led by the National Disaster Response Force (NDRF), search operations are continuing since Sunday.
Incensed by the "delay" in launching the rescue and search operations, locals on Sunday set fire to several boats in Shantipur's Nrisinghapur Ghat jetty and pelted stones at police men, injuring some of them.
Police had to fire tear gas shells to disperse the irate mobs.
The administration has denied any delay in the rescue and search operation.