Guwahati SSP AP Tiwari said the person has been identified as 25-year old Dilbag Singh, hailing from Jammu.
"He was apprehended today by city police and CRPF from a mall in Guwahati. He belongs to the Khalistan Zindabad Force, a militant group related to Punjab," he added.
The Assam Police has informed about the arrest to its counterparts in Punjab for taking his custody.
Tiwari said the information about the militant was provided by Punjab Police.