 However, by the time regular ARVN units arrived at their destination, the PAVN had already encircled the Don Luan military zone, so it was within range of the formidable PAVN long-range artillery guns.Even though the ARVN received extensive air support they could only send one company into Đồng Xoài, so Brigadier General Lê Nguyên Vĩ was forced to withdraw his forces from the area.At 5.37am on December 26, 1974, the PAVN 141st Regiment opened their attack on the ARVN base at Đôn Luân from four different directions, after 15 minutes of artillery bombardment from supporting artillery units.