Preceded by five B-52 strikes, which reportedly killed 300 North Vietnamese to the south, South Vietnamese forces arrive by helicopter to within two miles of An Loc in continuing efforts to relieve this besieged city. It had been surrounded by three North Vietnamese divisions since early April. The North Vietnamese had been holding An Loc under siege for almost three months while they made repeated attempts to take the city. The defenders suffered heavy casualties, including 2,300 dead or missing, but with the aid of U.S. advisors and American airpower, they managed to hold An Loc against vastly superior odds until the siege was finally lifted on June 18.