The Islamic State (IS) group claimed responsibility for Wednesday's attack on a Shia Muslim shrine in Shiraz, southern Iran, which Iranian state media said left at least 15 people dead.
An IS fighter opened fire on worshipers at the Shahcheragh shrine, '
killing at least 20 Shiites and injuring dozens more
', Amaq, the Sunni Muslim jihadist group's propaganda arm, claimed on Telegram .