Police identify first of 7 attackers

French police have identified the first of seven gunmen who killed at least 129 people in a wave of carnage claimed by the Islamic State group, as international investigators stepped up their probes into Paris' worst attacks.

French authorities on Saturday named the first attacker as 29-year-old Omar Ismail Mostefai, who was identified from a severed finger found at Bataclan concert hall, scene of the worst of the bloodshed.

IS jihadists said they were behind the gun and suicide bombing attacks that left a trail of destruction at a sold-out concert hall, at restaurants and bars, and outside France's Stade de France national stadium.