The first successful action of NVA armor in Vietnam was against the Lang Vei Special Forces camp on 6/7 February 1968 (they had already been used in the preceding Battle of Ban Houei Sane, which was just across the border in Laos however). Thirteen PT-76s, of the NVA 202nd Armored Regiment spearheaded an assault against approximately 24 Green Berets, 500 Vietnamese irregulars and 350 Laotian Royal soldiers. The defenders fought back with their 106 mm M40 recoilless rifle (one at the entrance took out three PT-76s until it was knocked out), and ineffectively with M72 LAWs (one-shot disposable 66 mm Light Anti-Tank Weapon). They requested support from nearby Khe Sanh, which was unable to help, as it too was under siege. The Lang Vei camp was overrun, with the PT-76s using their turret-mounted spotlight-equipped heavy machine guns to shoot down any irregulars who panicked and ran out of the underground bunkers. A few survivors broke out and were airlifted to safety.