France vows 'merciless' response after attacks kill 127

By Ingrid Melander and Marine Pennetier PARIS (Reuters) - An angry President Francois Hollande on Saturday promised a "merciless" response to a wave of attacks by gunmen and bombers that killed 127 people across Paris, describing the assault claimed by Islamic State as an act of war against France. In the worst attack, a Paris city hall official said four gunmen systematically slaughtered at least 87 young people at a rock concert at the Bataclan concert hall before anti-terrorist commandos laun