In 1957 alone, some 4,000 Algerian Muslim immigrants were killed in feuding between these two groups in mainland French cities.

From Small Wars, Faraway Places by Michael Burleigh. Page 321.

“The eight-year war in Algeria began as one between French government forces and indigenous Arab and Berber nationalists. It encompassed a civil war waged by the supposedly socialist Front de Libération Nationale (FLN), which practised widespread ‘compliance terrorism’ to enforce popular support, against the rival Mouvement National Algérien led by the veteran nationalist leader Messali Hadj, which probably enjoyed covert French support. In 1957 alone, some 4,000 Algerian Muslim immigrants were killed in feuding between these two groups in mainland French cities. The conflict ended with French right-wing Organisation de l’Armée Secrète terrorists declaring war on the French authorities and bombing and shooting their opponents in Algeria and in metropolitan France. The OAS alone killed as many people as died in the entire thirty-year Troubles in Northern Ireland between 1968 and 1998. It was the worst of the dirty wars waged by European colonial powers, eclipsing even Britain’s brutal campaign in Kenya.