 Among the units taken captive at Lạng Sơn was the 2nd Battalion of the 5th Foreign Infantry Regiment that contained 179 German and Austrian volunteers, whom the Japanese in vain tried to induce to change sides.On 23 September, the French Government protested the breach of the agreements by the IJA to the Japanese government.On the morning of 24 September, Japanese aircraft from aircraft carriers in the Gulf of Tonkin attacked French positions on the coast.