Intelligence agencies had intercepted a message relayed in Bodo language at around 1240 hours on December 23. The message was deciphered at 1440 hours and it suggested NDFB(S) was planning to attack Adivasi villagers along Assam-Arunachal Pradesh border around 1700 hours, sources in the know said.
The information was immediately conveyed to the Sonitpur district administration which in turn alerted Biswanath Chariali police station under which the area falls.
By the time police reached the two villages -- Sonajuli and Tinisuti -- everything was over and the NDFB attack resulted in more than 35 dead there.
A similar situation was at a place under Dhekiajuli police station of Sonitpur district and at Pakhiriguri and Ultapani in Kokrajhar district where the NDFB militants gunned down some more, sources said.
The day after of the attacks, Minister of State for Home Kiren Rijiju also said there were intelligence inputs but the forces could not reach the spots on time.