 At 03 : 00 on 31 January , twelve Vietcong sappers approached the Vietnamese Navy Headquarters in two civilian cars , killing two guards at a barricade at Me Linh Square and then advanced towards the base gate . The sound of gunfire alerted base sentries who secured the gate and sounded the alarm . A .30 @-@ caliber machine gun on the second floor of the headquarters disabled both cars and killed or wounded several sappers while the Navy security force organized a counterattack . Simultaneously a U.S. Navy advisor contacted the U.S. military police who soon attacked the Vietcong from adjoining streets , the resulting crossfire ended the attack , killing eight sappers with two captured . 
