Seven persons were arrested for allegedly selling pre-activated SIM card to NDFB-S militant.
Security forces arrested 12 top cadres, who included one central committee member, one deputy commandant and one platoon commander of the outfit.
The militants were apprehended in the joint operation by police, SSB and CRPF yesterday.
They were accused of massacre of the Adivasis at Pakriguri in Kokrajhar district on December 23.
At present, nearly 1.4 lakh people are staying at 68 relief camps in Kokrajhar.
The notification was issued after considering the law and order situation in Assam.
Assam government had recommended that the probe into these cases be handed over to the NIA.
Over 80 persons, many of them children and women, were killed in simultaneous attack in four villages.
Most of those taking shelter in Bengal’s camps are survivors of earlier violence.
The Assam government in a letter on Friday had recommended the investigation of these cases by the NIA.
Army chief Dalbir Singh announced deployment of 66 columns of troops in northern Assam in order to intensify operations.
The group has suffered two splits, and two factions have held talks with the government.
Songbijit hails from Chelaikhati village under Biswanath Chariali sub-division in Sonitpur district.
The cadres were mostly involved in extortion from local villagers as well as businessmen in the district.
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