At 00:30 on 31 January, a patrol from Company E,
4th Battalion, 12th Infantry Regiment detected a company-size PAVN/VC force approximately 10 km north of Bien Hoa, moving in the direction of Bien Hoa AB. Company E engaged the PAVN/VC supported by artillery fire killing 47 PAVN/VC. At dawn several
AH–1 Cobra gunships from the
334th Assault Helicopter Company joined the defense spraying the VC with rockets and machine gun fire which started fires causing the VC assault to lose its impetus. USAF losses were four killed in action with another dying of a heart attack, while 26 were wounded. PAVN/VC losses were 137 killed and 25 captured. One
A-37 and one F-100 were destroyed while a further 17 aircraft were damaged.
Attack on Long Binh Post Several dozen of the PAVN rockets exploded near the II Field Force and 199th LIB headquarters in the Plantation Compound () causing minimal damage. The acting commander of the 199th LIB, Col.
Frederic E. Davison, ordered three of his infantry companies operating north of Long Binh to attack the rocket launch site, while Weyand ordered the 9th Infantry Division to send the 1st Brigade from Bearcat Base. The VC 275th Regiment had taken up positions in a residential area known at the Widows' Village (), which housed the wives and families of dead ARVN soldiers and was located across Route 316 from the Plantation Compound. A VC commander captured later in the battle revealed that his orders were only to start the attack after several hundred rockets had hit the Plantation, but as the rocket sites had been neutralized before the rocket threshold was reached, the ground assault on the Plantation never began. Instead at approximately 03:30 the VC began firing across the road at the Plantation Compound being met by return fire from the perimeter bunkers. Some VC crossed Route 316 and took up firing positions in bush at the southern perimeter of the Plantation. At 04:00 a 60-man VC sapper team penetrated the northeastern perimeter of the base killing three MPs and entered the massive ammunition dump () where they planted eighteen
Satchel charges before being forced to withdraw by the 720th Military Police Battalion. Bomb squads disarmed seven of the charges, but at 04:30 the remainder exploded with three igniting pallets of artillery shells and their
Propellant bags causing a massive explosion, blast wave and mushroom cloud. However the ammunition storage bunkers prevented a chain reaction and the lost munitions were easily replaced with no impact on supply. At approximately 05:30, the
2nd Battalion, 47th Infantry Regiment, mounted on
M113 Armored Cavalry Assault Vehicles (ACAVs) coming from Bearcat approached the Plantation from the southwest and formed a skirmish line to engage the VC, while helicopter gunships from the
3rd Squadron, 17th Cavalry Regiment swept in to rocket and machine gun the VC positions. At 08:00 the VC south of the Plantation withdrew into the Widows’ Village. Company B,
2nd Battalion, 39th Infantry Regiment had arrived by helicopter from Bearcat and joined up with 2/47th Infantry to sweep the Widows’ Village. By late afternoon the 275th Regiment retreated north, leaving over 200 dead. US losses in the fighting in the Widow's Village were three dead.
Ho Nai The town of Ho Nai () was located on Highway 1 north of the Widow's Village and Long Binh Post. Its predominantly Catholic population was made up of many Vietnamese who
fled North Vietnam in 1954 after the
Viet Minh victory. When the Company F, 51st Infantry LRRP team reported PAVN/VC moving past their position a reaction force from Company C, 4/12th Infantry mounted on ACAVs was sent to investigate. The unit left their position at Firebase Concord north of Biên Hòa and moved east proceeding along trails north of Ho Nai towards the LRRP position. At 03:45 the unit engaged the VC/PAVN with two ACAVs being quickly knocked out by RPG fire. By dawn the VC/PAVN were retreating northwards pursued by helicopter gunships and at 06:15 Company C, 4/12th Infantry began moving north in pursuit, intending to pin the PAVN/VC against a force from Company B,
2nd Battalion, 3rd Infantry Regiment which was moving south. At 07:30 the VC/PAVN force stopped and made a stand in a cemetery where they continued to be hit by the gunships and the ACAVs of Company C. At 08:00 Company C was joined by a force from 2/47th Infantry and they proceeded to methodically kill all the PAVN/VC in the cemetery. After the cemetery had been cleared Company B, 2/3rd Infantry joined Company C, 4/12th Infantry and they made a night defensive perimeter north of Ho Nai, while the 2/47th Infantry was withdrawn to Biên Hòa. In the late afternoon of 31 January after clearing the Widow's Village 2/47th Infantry advanced into Ho Nai from the south, the town appeared deserted. As the 2/47th Infantry approached the town a Vietnamese warned that it contained many VC and the VC then launched an ambush on the column knocking out 3 ACAVs with RPGs setting off a four-hour battle as the US forces engaged the VC position and rescued the survivors in the damaged ACAVs. By the evening the 2/47th Infantry withdrew into the Long Binh perimeter. On 1 February Company B, 2/3rd Infantry, Company C, 4/12th Infantry and elements of 2/47th Infantry swept Ho Nai finding only dead VC/PAVN and civilians who had been murdered by the VC or killed in the fighting in the town. On the evening of 1 February three platoons from Company C, 4/12th Infantry and two platoons from Company D,
17th Cavalry Regiment were ordered 2 km north of Ho Nai to establish an outer defense against any renewed VC/PAVN attack. The VC/PAVN attacked the position that night in a six hour long assault which was met initially by US mortar and artillery fire, then helicopter gunships and then napalm strikes. A force from Company C, 2/3rd Infantry mounted on ACAVs was sent north from Ho Nai and pinned the VC/PAVN in a crossfire. At dawn on 2 February the US counted approximately 50 PAVN/VC dead in the area and captured three VC.
Biên Hòa A PAVN/VC attack on the prisoner of war camp in Biên Hòa which held over 2000 prisoners was repulsed by a platoon from Company C, 4/12th Infantry and a platoon from Company D, 17th Cavalry and their ACAVs. 26 PAVN/VC were killed in the attack and several captured. ==Aftermath==