ISPR said it was Rawalpindi Corps. Although i live in Rawalpindi but I simply don't know
This is what you get from wiki
X Corps headquartered at Rawalpindi
12th Infantry Division headquartered at Murree
19th Infantry Division headquartered at Mangla
23rd Infantry Division headquartered at Jhelum
Force Command Northern Areas headquartered at Gilgit
111th Infantry Brigade headquartered at Rawalpindi
8th Armoured Brigade headquartered at Kharian
Independent Artillery Brigade
also about SSG
The Special Services Group (SSG) is an
independent commando regiment/corps of the Pakistan Army. It is an elite special operations force similar to the United States Army Special Forces (Green Berets) and the British Army's SAS.
Official numbers are put at 2,100 men, in 3 battalions; however the actual strength is classified. It is estimated to have been increased to 4 Battalions, with the eventual formation of 2 Brigades of Special Forces (6 Battalions).
Also i don't think elite forces are trained for patrolling. ( correct me if i am wrong )