Three suspected militants of the National Democratic Front of Bodoland (NDFB) and an alleged member of Manipur's Kangleipak Communist Party (KCP) were arrested in separate incidents in Guwahati on Thursday.Police said, Ponkha Basumatary, Gaurav Boro and Parikshit Boro, belonging to NDFB's publicity wing, were arrested from Latasil area while a KCP militant, identified as S Ramesh alias Ramen, was arrested from Paltanbazar area. Police have stepped up search operations in Guwahati following intelligence reports that militant outfits, particularly the NDFB, was planning to carry out subversive activities in the run up to the Independence Day celebrations.