 Outside the city proper two Viet Cong battalions attacked the U.S. logistical and headquarters complex at Long Binh . Biên Hòa Air Base was struck by a battalion , while the adjacent ARVN III Corps headquarters was the objective of another . Tan Son Nhut Air Base , in the northwestern part of the city , was attacked by three battalions . A combat @-@ ready battalion of ARVN paratroopers , awaiting transport to Da Nang , went instead directly into action and halted the attack . A total of 35 communist battalions , many of whose troops were undercover cadres who had lived and worked within the capital or its environs for years , had been committed to the Saigon objectives . By dawn most of the attacks within the city center had been eliminated , but severe fighting between Viet Cong and allied forces erupted in the Chinese neighborhood of Cholon around the Phú Thọ racetrack , southwest of the city center , which was being used as a staging area and command and control center by the North Vietnamese . Bitter and destructive house @-@ to @-@ house fighting erupted in the area . On 4 February , the residents were ordered to leave their homes and the area was declared a free fire zone . Fighting in the city came to a close only after a fierce battle between the ARVN Rangers and PAVN forces on 7 March . 
