Who are the Senegalese men joining the Islamic State group?

One of the young Senegalese men who left to wage jihad under the banner of the Islamic State (IS) organisation in Libya was a promising young medical student named Sadio Gassama. Now he and his fellow fighters proudly post on Facebook about their new lives as members of the jihadist group. This comes as a shock to Sadio’s former classmate, who remembers Sadio as pious, but not as someone who’d wage jihad.