The curfew has been announced as a precautionary measure to prevent the movement of extremists, anti-social elements and unlawful activities on Monday.
Assam shares a 512-km-long border with Nagaland.
A statement issued by the Nagaland government said that the night curfew would continue till December 9 and will be in force from 6 pm to 6 am.
Quoting the Sivasagar district administration's notification, the Nagaland government statement said that movement of any person, group of persons and vehicular traffic is prohibited during the period of the night curfew.
However, the order also mentioned that, magistrates, security personnel, and civil officials deployed on duty are exempted from the purview of the prohibitory order.