On the morning of 3 June, students and residents discovered troops dressed in plainclothes trying to smuggle weapons into the city. The students seized and handed the weapons to Beijing Police. The students protested outside the Xinhua Gate of the Zhongnanhai leadership compound and the police fired tear gas. Unarmed troops emerged from the Great Hall of the People and were quickly met with crowds of protesters. Several protesters tried to injure the troops as they collided outside the Great Hall of the People, forcing soldiers to retreat, but only for a short while.
On the evening of 3 June, state-run television warned residents to stay indoors but crowds of people took to the streets, as they had two weeks before, to block the incoming army. PLA units advanced on Beijing from every direction—the 38th, 63rd and 28th Armies from the west, the 15th Airborne Corps, 20th, 26th and 54th Armies from the south, the 39th Army and the 1st Armored Division from the east and the 40th and 64th Armies from the north.
At about 10 pm the 38th Army began to open fire upward into the air as they traveled east on West Chang'an Avenue toward the city centre. They initially intended the warning shots to frighten and disperse large crowds gathering to stop their progress. This attempt failed. The earliest casualties occurred as far west as Wukesong, where Song Xiaoming, a 32-year-old aerospace technician, was the first confirmed fatality of the night. Several minutes later, when the convoy eventually encountered a substantial blockade somewhere east of the 3rd Ring Road, they opened automatic rifle fire directly at protesters. The crowds were stunned that the army was using live ammunition and reacted by hurling insults and projectiles. The troops used expanding bullets, prohibited by international law for use in warfare, which expand upon entering the body and create larger wounds.
At 10:16 pm, the loudspeakers controlled by the government warned that troops may take "any measures" to enforce martial law.
By 10:30 pm, news of bloodshed to the west and south of the city began trickling into the Square, often told by witnesses drenched in blood. At midnight, the students' loudspeaker announced news that a student had been killed on West Chang'an Avenue, near the Military Museum and a somber mood settled on the Square. Li Lu, the deputy commander of the student headquarters, urged students to remain united in defending the Square through non-violent means.
At about 10:30 pm, the advance of the army was briefly halted at Muxidi, about 5 km west of the Square, where articulated trolleybuses were placed across a bridge and set on fire. Crowds of residents from nearby apartment blocks tried to surround the military convoy and halt its advance. The 38th Army again opened fire, inflicting heavy casualties.