On July 25, 1948, the Cao Bằng encampment was itself attacked and held out for three days with two companies defending against two battalions of Việt Minh.

[1] In February 1949, five Việt Minh battalions and mortar units took a French post at Lào Cai, and resumed ambushes through the monsoon season.

On September 3, 1949, 100 vehicles left That Khe in a reinforced convoy which travelled a distance of 16 miles (26 km) through infantry screens.

The French, reduced to one soldier per vehicle due to troop numbers, were ambushed by automatic fire.

[1] The campaign at Cao Bằng resulted in a change in convoy practices for the remainder of the war.