The penitentiaty administration tag is pictured on a warden's jacket as prison wardens gather outside the high-security prison of Vendin-le-Vieil, northern France, on January 12, 2018, a day after three prison guards have been injured in a blade attack by a German Al-Qaeda militant. Islamic convert Christian Ganczarski, serving an 18-year sentence over the 2002 blast in Djerba that killed 21 people, launched himself at prison officers after hearing he may face extradition to the US in connection with 9/11 investigations, according to union sources. / AFP PHOTO / Denis Charlet