Liu now fell back up the Red River to Thanh Quan, only a few days march from the frontier town of Lào Cai. He was now in a position to retreat into China if the French pursued him. Several hundred Black Flag soldiers, demoralised by the ease with which Courbet and Millot had defeated the Black Flag Army, surrendered to the French in the summer of 1884. One of Millot's final achievements was to advance up the Clear River and throw the Black Flag Army out of Tuyên Quang in the first week of June, again without a single French casualty. If the French had seriously pursued Liu Yongfu after the capture of Tuyên Quang, the Black Flags would probably have been driven from Tonkin there and then. But French attention was diverted by the sudden crisis with China provoked by the Bắc Lệ ambush (23 June 1884), and during the eventful summer of 1884 the Black Flags were left to lick their wounds.