CAIRO, March 23 (Reuters) - Islamic State released on Saturday a photo of what it said were the four attackers behind a shooting rampage that killed at least 143 people in a concert hall near Moscow on Friday, the militant group’s Amaq news agency said on Telegram.
“The attack comes within the context of a raging war between the Islamic State and countries fighting Islam,” Amaq added in a statement citing security sources.
Islamic State claimed responsibility for the attack but there were indications that Russia was pursuing a Ukrainian link, despite emphatic denials from Ukrainian officials that Kyiv had anything to do with it.
ISIS is Sunni (the majority of Muslims) and the Sunni extremists like ISIS hate the Shia Muslims (mostly Iraq and Iran).
I have a hard time believing that ISIS would give a shit about more moderate Sunnis.