Darrang deputy commissioner MS Manivannan said curfew was imposed in 25 villages to stop any deterioration of the situation.
The curfew would be in force till further orders and till the situation improves, he added.
A group of people attacked another group at Udmari village, after suspecting the second group to be of dacoits. A total of 13 people were injured in the incident, a district administration officer said.
Five of the injured were taken to the Guwahati Medical College and Hospital for treatment.
Additional security has been deployed in and around the area, police said.
The district administration has ordered a magisterial probe into the incident.