As part of the May Offensive, PAVN Major General Chu Huy Mân Commander of Military Region 5 ordered the 3rd Division to attack the 1/50th Infantry in Bình Định Province with a series of large-scale ambushes.

By 10:00 the force had turned west off Highway 1 towards An Bao and were crossing some dry rice paddies in a clearing when they saw a group of approximately 15 PAVN run into the tree line.

As they were preparing to move out, the position was hit by rocket-propelled grenades (RPG) and recoilless rifle fire, which disabled the command and medical vehicles.

The remaining 4 M113s and some soldiers on foot retreated through their entry point into the clearing and headed back to Highway 1 leaving behind 15 men in a small perimeter a few 100 metres (330 ft) northwest of the disabled M113s.

The previously dry paddy fields were now filling up with water from a dike that had been deliberately opened or destroyed in the bombing, and the ground was now too muddy to be crossed.

[1]: 551 At 03:30 on 6 May, the PAVN attacked the northwest of the U.S. perimeter with over a hundred soldiers advancing behind a hail of mortar and RPG fire that detonated an ammunition stockpile, injuring several Americans.