Russia claims to have “proof” that the perpetrators of the attack which left 143 dead near Moscow had links with “Ukrainian nationalists’ Washington denounces “absurd propaganda” The attack, which took place Friday evening in a large concert hall, was claimed by the jihadist organization Islamic State (IS) but Russian officials say Ukraine and the West were the instigators. Ukraine vigorously denies any involvement in this massacre, accusing Moscow of wanting to “  blame  ” it on Kiev.