In the "Yen Bai Uprising of 1930" against the French colonial rule, many French army officers were killed. To putdown the uprising, the French resorted to aerial bombardment and even napalm bombs were used. The rebellion was put down ruthlessly by the French within a day; many Vietnamese soldiers and 12 VNQDĐ leaders were executed. Following this repressive action by the French, there were frequent anti-colonialist strikes and riots throughout the country, which were all put down ruthlessly. This resulted in breaking the backbone of the VNQDD and the Communist Party in North Vietnam for a considerable period.