Terror returns with nightclub massacre

Islamic State group says without providing evidence that one of its fighters carried out attack

US anti-terror strategy came under fresh scrutiny after a gunman previously cleared of jihadist ties launched a hate-fueled rampage in a Florida gay club that left 50 dead.

As the worst mass shooting in the country's modern history erupted on Sunday, Orlando police blasted their way into the Pulse nightspot and shot the attacker dead.