A joint team of the army and Assam Police Tuesday killed a Karbi militant and arrested seven others from different rebel outfits, officials said.Defence spokesperson Lt. Col. Suneet Newton said the Karbi Peoples' Liberation Tigers (KPLT) militant was killed by the army near Hemron village in Karbi Anglong district.An M16 rifle and ammunition were recovered from the militant.The army and police carried out an operation in Rongsoi along Meghalaya-Assam inter-state border and arrested five militants of the Garo National Liberation Army (GNLA).The GNLA cadres were carrying out extortion and trying to spread terror in the area, he said. Five pistols and ammunition were seized from them.Another team of security personnel apprehended two militants of the anti-talk faction of the National Democratic Front of Bodoland (NDFB) from near Tipkai in Kokrajhar district. Two pistols and ammunition were recovered from them.The two were assigned by the top brass of the outfit to recruit new cadres.Both were involved in extortion and were providing information about movement of security forces in Kokrajhar and Chirang districts.