A senior police officer said the accused Faridul Islam was caught by villagers as he was escaping after the news of death of local vegetable vendor Zaheer Hussein allegedly stabbed by Faridul earlier in the day spread in the locality.
The villagers confined the accused in a room and tried to set it aflame when a strong police force reached the area and bore the brunt of mob attack when it was rescuing Faridul.
The accused was later taken to Jalpaiguri Sadar Hospital in critical condition, the officer said.
Police raids were on the village led by an ASP ranked officer.
The villagers complained to the police that Faridul stabbed Zaheer while he was returning from a local fair when the trader refused to meet his extortion demand.