The ARVN defenders of An Lộc were made up of several units of the 5th Division, including the Division's 8th Regiment with about 2,100 men; the 7th Regiment which was short one battalion and only had 850 men; the 9th Regiment, most of which was destroyed at Lộc Ninh, had only had 200 men; Task Force 52, 500 men; the 3rd Ranger Group, 1,300 men; as well as Binh Long Provincial Regional Force, Popular Forces, and People's Self-Defense Forces (PSDF), about 2,000 men. The defenders were later reinforced by the elite 81st Ranger Group and the 1st Airborne Brigade, brought in by air because QL-13 was blocked by the PAVN. Because the ARVN defense had little artillery, it was heavily reliant on U.S. air support. Other reinforcements consisted of the 21st Division, which was plagued by a very slow move from the Delta area in the south of the country and cleared QL-13 after protracted fighting.