Three students were killed and eight injured on Saturday in police firing and a resultant stampede in Moirabari, promoting authorities to impose curfew in the town.
Police opened fire when a group of irate students went on the rampage and set a police station of fire, officials said.
They said two groups of students were involved in a clash during elections to the Moirabari College Students' Union and police arrested some student leaders of both factions for causing trouble.
Irate members of both factions then marched to Moirabari police station, gheraoed it, went on the rampage and then set the police station ablaze, officials said.
Police then opened fire, killing one student, they said.
Morigaon's Deputy Commissioner Shabir Hussain, who rushed to the spot with the superintendent of police, said two other students were killed and eight injured in a stampede sparked by the police firing.
Additional security forces were sent to the town.