The security forces, acting on specific information, nabbed the militants from Gohpur area near Assam-Arunachal Pradesh border of the district, said Manabendra Roy, SP of Biswanath Chariali police district.
A 7.65 pistol, six rounds of ammunition, some documents, a mobile phone and some SIM cards were recovered from the militants, he said.
The arrested militants have been identified as Rohit Narzary, Prosen Basumatary, Asish Basumatary and Rajib Uzir.
Altogether 13 NDFB(S) militants have been arrested so far by security forces since the killing of 30 persons on December 23 by the NDFB(S) in Phulbari locality under Biswanath Chariali police station, Roy added.