The Army and Assam police, in a joint operation, killed an alleged hardcore ULFA militant and apprehended a female cadre following a gun-battle at Charaideo near the Assam-Arunachal Pradesh boundary in Sivasagar district of Upper Assam on Monday.

Security personnel recovered one AK 56 rifle, two magazines, one grenade, a pistol and a cellphone from the slain militant identified as Rajib Saikia. The security personnel also apprehended Satyama Bailung alias Mumu.

The police said the slain militant was a close aide of the 'B' company commander Sujit Mohan of 28th battalion, the main strike force of the ULFA.

The Army, of late, has geared up vigil all along the inter-state boundary with Arunachal Pradesh in Upper Assam. The dense forests across the inter-state boundary inside Arunachal Pradesh have become a base of the 28th battalion of the ULFA.

Security sources said a number of senior leaders of the 28th battalion of the ULFA had been frequenting Arunachal Pradesh, taking advantage of  the lack of adequate presence of police forces.