Shortly after midnight on 10 February, about 50 Vietnamese soldiers (Tirailleurs indochinois) of the 4th Regiment of Tonkinese Rifles within the Yên Bái garrison turned on their French officers, with assistance from about 60 civilian VNQDĐ members who invaded the camp from the outside.

The main leaders of the VNQDĐ were arrested, tried and put to death, effectively ending the military threat of what was previously the leading Vietnamese nationalist revolutionary organisation.

[4] Initially, military resistance to French rule came through the Cần Vương movement led by Tôn Thất Thuyết and Phan Đình Phùng, which sought to install the boy Emperor Hàm Nghi at the head of an independent nation.

[7] A minority felt that even though there was a danger that French crackdowns would irreparably weaken the party, they should try and bide their time and go into hiding in the mountainous Hoa Binh Province and focus on writing propaganda books and pamphlets, and take an extended period to prepare a large armed attack.

[9] Since the VNQDĐ was only strong in the northern areas of Vietnam, the attacks were to be staged in the Red River Delta, and the garrison at Yen Bay was identified as a key point.

[7] Although armed resistance had died down since World War I, the Red River area of northern Vietnam, which included Yên Bái, had been a disproportionate source of nationalist militancy since the French colonisation.

At this meeting, the VNQDD leader Nguyễn Thái Học asked for a map of the French military airfield at Bach Mai and assigned Duong the responsibility of recruiting personnel for an attack.

Discussions were also held for the finalisation of plans of attack on Nam Dinh, Lang Son, Haiphong, Bac Ninh and Mong Cai, although an intended assault on the capital Hanoi was still not ready.

[16] Despite the fact that Duong's cover had been blown, the French authorities still continued to receive some intelligence indicating that attacks were planned for northern Vietnam during the Lunar New Year period in early February.

He said that he had the support of local soldiers at the Lào Cai garrison and would launch attacks on French border posts,[17] so exiled VNQDĐ members could re-enter Vietnam and join the uprising.

[21] More than 100 bombs by around 20 militants were made at the home of Nguyen Dac Bang, who also organised the drafting and printing of propaganda leaflets—for distribution among soldiers and civilians alike—and led the recruitment of villagers in his area.

[28] In addition, the insurrectionists had failed to liquidate the Garde indigène (native gendarmerie) post of Yen Bay town and were unable to convince the frightened civilian population to join them in a general revolt.

[25][31] Nhu's men traversed the streets and avoided passing the French administrative offices and arrived at the military complex, shouting at the Vietnamese sentries to open the doors and join the revolt.

[34] Aware of what had happened in the upper delta region, Chinh abandoned plans for an attack on the Sơn Tây garrison and fled, but he was captured a few days later by French authorities.

[37] The troops at Yên Bái initiated a security crackdown by banning local boats from travelling along the Red River and preventing the transport of merchandise by other means, resulting in 10,000 piasters of lost revenue in the space of a month.

[37] The anthropologist and historian Hy V. Luong said that although the failure of the attack was not unexpected given the imbalance in resources, he also noted that the VNQDD support base was overwhelming restricted to the educated urban class rather than the rural masses, and was thus not suited for a protracted guerrilla given that it had not cultivated the population for that purpose.

[41] The largest number of death penalties were handed down by the first Criminal Commission, which had convened at Yen Bay on 27 February, just 17 days after the attacks, to try those implicated in the mutiny and nearby insurrections.

[49] Those associated with the colonial regime in Vietnam strongly advocated harsh punishments and a further expansion of power, while domestic authorities in France took a more moderate stance in public due to the presence of leftist political movements.

[49] Eventually the local bureaucrats walked out and the French officials voted to increase the powers of the Governor-General of Indochina, purportedly allowing him to review capital punishment cases without requiring final approval from Paris.

[52] This occurred in defiance of a court order that deemed the government's charges against them to be unfounded, and led to combative debate in the National Assembly between the Communist and Socialist Parties on one side and the conservative majority on the other.

[51] Due to the high number of death sentences handed down, the Minister of Colonies intervened with Governor-General Pasquier, so that no execution could be performed unless the case had been reviewed by a pardoning commission.

[56] The magazine Phu Nu Tan Van (Women’s News) disseminated pictures of the condemned VNQDĐ members in one of their issues, raising the stature of the revolutionaries in death.

I judged that only a punishment capable of terrifying those tempted to participate in the rebellion could totally reassure the sane and peaceful elements of the population regarding our will to defend French sovereignty in that land and to stop the movement cold.

According to Patrice Morlat, "545 tirailleurs and warrant officers were the object of sanctions: 164 were transferred into disciplinary companies in Tonkin, 94 to Africa..., 57 were handed over to the civilian jurisdiction, and 160 were reduced to the ranks and put on leave without pay."

[61] Many villages heavily affected by the mutiny and the subsequent crackdown saw a sudden increase in conversions to Catholicism, as many hoped that French priests would lobby the authorities for the sentences imposed on their friends and relatives to be reduced.

[61] In 1936, the leftist Popular Front came to power, resulting in a wave of sentence reductions, albeit with parole conditions that forced them to stay in their villages and periodically report to local authorities.

[63] In the long run, Yên Bái allowed the Indochinese Communist Party of Ho Chi Minh to inherit the VNQDĐ's status as the leading anti-colonial revolutionary movement.

[75] The French reaction to the mutiny included military punishments, new regulations, SRM institutional reform, reductions in the numbers of Vietnamese serving or working in France and increased specialisation amongst the units making up the garrison of Indochina.

[77] The most sweeping proposal was that made by Resident Superior Robin who wanted to "completely and radically abolish all regiments of Tirailleurs tonkinois (Vietnamese infantry) serving in the delta and the middle regions" and replace them with "white [Foreign] Legion or even North African battalions".

[80] Prior to the mutiny, the Department of War in Paris had clearly indicated that it would not be able "to provide for one more European battalion in Indochina under the 1931 Budget" due to fiscal constraints, manpower shortages and organisational problems.