▁the ▁local ▁police ▁station ▁which ▁had ▁already ▁been ▁abandoned ▁by ▁the ▁South ▁Vietnam ese . ▁By ▁ 8   am ▁the ▁prisoners ▁had ▁captured ▁all ▁former ▁South ▁Vietnam ese ▁infrastr ucture ▁and ▁assets , ▁including ▁ 2 7 ▁aircraft , ▁as ▁the ▁remaining ▁AR V N ▁soldiers ▁at ▁the ▁C ô n ▁S ơ n ▁air port ▁also ▁surrender ed . ▁ ▁On ▁the ▁evening ▁of ▁May ▁ 2 , ▁ 1 9 7 5 , ▁the ▁re bel ▁prisoners ▁on ▁C ô n ▁ Đ ả o ▁Island ▁successfully ▁establish ▁communic ations ▁with ▁North ▁Vietnam ese ▁military ▁units . ▁To ▁prepare ▁for ▁the ▁arrival ▁of ▁the ▁North ▁Vietnam ese , ▁the ▁Pro vis ional ▁Committee ▁moved ▁to ▁set ▁up ▁a ▁tren ch ▁system ▁around ▁the ▁island ▁to ▁defend ▁against ▁a ▁possible ▁South ▁Vietnam ese ▁or ▁U . S . ▁counter - att ack . ▁On ▁the ▁morning ▁of ▁May ▁ 5 , ▁ 1 9 7 5 , ▁the ▁North ▁Vietnam ese ▁ 1 7 1 st ▁and ▁ 1 7 2 nd ▁Naval ▁Reg iments ▁land ed ▁on ▁C ô n ▁ Đ ả o ▁Island ▁with ▁elements ▁of ▁the ▁P AV N ▁ 3 rd ▁Division . ▁Through out ▁the ▁day ▁regular ▁North ▁Vietnam ese ▁military ▁units ▁and ▁the ▁re bel ▁prisoners ▁coordin ated ▁their ▁forces , ▁to ▁establish ▁control ▁over ▁the ▁rest ▁of ▁the ▁C ô n ▁ Đ ả o ▁Arch ip el ago . ▁ ▁After math ▁After ▁more ▁than ▁two ▁months ▁of ▁planning ▁and ▁combat ▁operations