Islamic State released 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 empathic denials from Ukrainian officials that Kyiv had anything to do with it.

Russian authorities said on Saturday they had arrested 11 people including four suspected gunmen in connection with the attack.