The Chinese People's Liberation Army (PLA) began their operations at 05:00 on 17 February[5] with a barrage of more than 6,000 artillery shells pounding on Vietnamese strongpoints and gun positions.

[5] Waves of PLA troops from the 55th Army quickly overwhelmed Hill 386, a position situated 1.5  km south of the border, killing 118 Vietnamese soldiers.

[7] Though pockets of resistance were continued near the Friendship Pass and in Đồng Đăng, most of the Vietnamese defense was by then undertaken by the Vietnam People's Army (VPA) 12th Regiment southerly in the area around the hamlet of Thâm Mô.

The fort, together with Thâm Mô and Hill 339, created a triangular mutually-supporting defensive structure, which was able to provide fire suppression against any attack on Đồng Đăng.

On 18 February, a Vietnamese counter-attack launched by the VPA 2nd Regiment drove PLA units back to their assemble positions on Hills 409, 611, and 675; this pattern was repeated on the following days.

[16] On (21 February), after receiving reinforcements, Chinese troops renewed their attack on the French Fort, securing most of the ground around it in a four-hour engagement.

After unsuccessful attempts to negotiate, the Chinese then used gasoline, explosives, and flamethrowers to demolish the fort, killing approximately 800 Vietnamese soldiers and civilians sheltering inside.