 The 32nd Regiment then deployed into the Tau O area () a further 5km north, where they ran into the 209th Regiment's well-prepared blocking positions which stopped the Division's advance for 38 days despite extensive artillery and air support including B-52 strikes.This stalemate would continue until the PAVN withdrew from An Lộc.On 15 May a task force of the 15th Regiment, 9th Division which was redeployed from the Mekong Delta and the 9th Armored Cavalry Squadron, 21st Division moved north, east of Route 13 bypassing the Tau O roadblock to establish a fire support base at Tan Khai () 10km south of An Lộc.