861 Regiment (Laleali & Picquet 707) traces its origin from the Border Scouts Battalion.

121 Heavy Mortar Battery participated in the Indian Army United Nations peacekeeping mission in Congo under 99 Infantry Brigade.

The devastating shelling by the Regiment on 3 and 4 December 1971 helped beat back the attack on Picquet 707.

The shelling on 6 and 7 December 1971 similarly prevented the attack on Laleali.

[4] The Regiment along with 8 Jammu and Kashmir Militia (now Light Infantry) were awarded the battle honours Laleali and Picquet 707.