French police launched nationwide raids early on Monday to dismantle a network that was sending jihadists to Syria, a police source said. Elite and anti-terror police units descended on around a dozen targets, mostly in the southern region of Toulouse, but also around Paris and in the northern region of Normandy, the source told AFP, on condition of anonymity. It was not immediately clear how many people were arrested. In recent months in France - which has Europe's largest Muslim population - there has been growing concern over the hundreds of nationals joining jihadist groups in Iraq and Syria. The new reality was driven home in a video from the Islamic State (IS) group, released in mid-November, showing three Kalashnikov-wielding Frenchmen burning their passports and calling on Muslims to join them or stage attacks in France.