The militant, identified as Mithun Rabha alias Rocky, was apprehended by a team of City Police from Rajaduar area of North Guwahati, police said.
A grenade, cash and mobile handsets were recovered from the militant who was allegedly involved in an attack on CRPF personnel on August 9 at Khardang under Krishnai police station in Goalpara districts.
Rabha was also allegedly involved in issuing extortion notes to several people and organisations.