Staff of Fleury-Merogis prison, south of Paris, staged a blockade of the facility on Monday, January 15, in protest against dangerous working conditions and insufficient protection against attacks by inmates.

Several prisons across France were blockaded, with protests sparked by a recent attack on three prison guards in Vendin-le-Vieil, according to RTL France.

France24 reported that prison unions called for a continuation of the blockades for Tuesday, January 16.

Fleury-Merogis, Europe’s largest prison, has been reported as a center of Islamic radicalization, with past inmates including Amedy Coulibaly, the hostage taker in the January 2015 kosher supermarket siege; Cherif Kouachi and Djamel Beghal, the Charlie Hebdo attackers; and Salah Abdeslam, a suspect in the November 2015 Paris attacks. Credit: Twitter/Valentin Demay via Storyful