[3] The conflict quickly escalated, as evidenced by the remarks of the Socialist Minister of the Interior, François Mitterrand: "I will not agree to negotiate with the enemies of the homeland.

[5] Popular support for the FLN was still rather low and many of the Algerian Muslim elite advocated for a peaceful resolution of the conflict through conciliatory agreements with the French government.

[9] That made Aussaresses deduce that the spike in flour sales must have been because the FLN was concentrating men in the hills above Philippeville, which could mean only that an operation was due to start soon.

[9] On 20 August 1955, a few hundred FLN members gathered crowds of several thousand local Muslim civilians, who were influenced by motivations of religious[10] and racial hatred.

[11] False rumours were spread of an imminent landing by Egyptian troops,[12][13][14] and the Muslim groups were directed towards various settlements in the Constantinois during a series of co-ordinated raids.

A large mob of several thousands civilians, led by FLN members, launched a general assault on the city with the aims of attacking Europeans and moderate Muslim personalities[14][15] and taking over the police station's weaponry.

[17] The mob was composed of hundreds of Muslims, both men and women, who were mostly armed with farming tools, axes, sharpened shovels, or knives and were led by 25 FLN members.

[18] Some of the local Muslim inhabitants who had initially watched without reacting eventually joined the excited mob as it massacred Europeans under chants of Allah Akabar that blended with Algerian women's ululations.

[14][20] Near El Khroub, a crowd of a few hundred ill-armed Muslim civilians, including women and children, led by a few FLN members, launched an assault on a French military outpost that was held by 150 soldiers.

[32] Haïm Benchetrit was forcibly pulled out of the vehicle, before being castrated and choked to death with his own genitals in front of his wife and their three children, aged 11, 5 and 3, who were then killed.

The total death toll of the French reprisals is uncertain (estimates vary from 1,200 to 12,000), but as at Setif ten years earlier, the number of Algerians killed in retaliation for the initial massacre of Europeans was disproportionate.

[38] The French reporter Robert Lambotte took a photograph depicting the lined up bodies of executed Algerians in the stadium and published it in the communist newspaper L'Humanité, which sparked national outrage in France.

[53] As such, the operation was thus considered a great success by Zighoud despite its failure to take the much-needed weapons from the targeted military outposts and police stations and the relatively small number of Europeans killed compared to the Algerian death toll.

[54] Despite the undeniable political success of the operation, Zighoud's cynical disregard for Algerian lives was frowned upon by several high-ranking members of the FLN.

Abane Ramdane and Larbi Ben M'hidi notably criticized his decision to send barely-armed Algerian civilians with almost no weapons to a certain death for a result of fewer than 100 Europeans being killed.

[60] Jacques Soustelle, the recently-appointed Governor of Algeria, who had thus far defended conciliatory approach on Algerian nationalism, was profoundly traumatized by his visit at the El-Halia mine after the attacks.

[62][37][63] The French pied-noir intellectual Albert Camus, who had written several articles to bring attention on the condition of native Algerians,[64] was appalled by the horrific massacre of European children and completely rejected the FLN as terrorists.