On 15 April the situation on the battlefield began to change as PAVN artillery stopped their shelling of Xuân Lộc, but started pounding Bien Hoa Air Base instead. In just one day, the RVNAF 3rd Air Force Division at Bien Hoa was forced to cease all operations due to continuous PAVN artillery bombardments. To continue their support of ground troops at Xuan Loc, the RVNAF mobilised the 4th Air Force Division based at Binh Thuy Air Base to conduct further missions. On the same day, an artillery bombardment of 1,000 rounds fell on the headquarters and 3rd Battalion, 52nd Regiment, an artillery battalion, and elements of the 5th Armored Cavalry Squadron, four 155 mm and eight 105 mm howitzers were destroyed, and the PAVN 6th Infantry Division and the 95B Infantry Regiment defeated a combined ARVN formation which included the 52nd Task Force and the 13th Armored Squadron west of Xuân Lộc. On 16 and 17 April, the PAVN 6th Infantry Division and the 95B Infantry Regiment defeated the ARVN 8th Task Force and 3rd Armored Brigade, when the ARVN tried to recapture the military zone of Dau Giay. Around Xuân Lộc the ARVN 43rd and 48th Infantry Regiments, as well as the 1st Airborne Brigade, suffered heavy casualties as PAVN infantry units attacked them from all sides. The armored task forces on Route 1 had to pull back; half of their equipment had been destroyed. The 1st Airborne Brigade, frustrated in its attack toward Xuân Lộc, withdrew through the plantations and jungles toward Bà Rịa in Phước Tuy Province.