The class XI student of Amguri Higher secondary School had gone with another girl from her neighbourhood to catch fish in Kanamakra river in No1 Baldi village when a group of unknown attackers killed her, police said.
The other girls managed to escape and report the matter to the villagers, who informed police, the sources said.
The local people claimed that the girl was raped and killed.
As a preventive measure, the district administration imposed night curfew from 6 pm to 6 am in Chirang, Amguri and Bijni police station areas today.