- Moscow attack: Putin says all four suspects arrested after 133 killed at concert hallBBC.com
- Putin says gunmen who raided Moscow concert hall tried to escape to Ukraine. Kyiv denies involvementThe Associated Press
- US ‘strongly condemns’ Moscow terrorist attackThe Hill
- Live updates: Shooting at Moscow concert venue leaves over 130 deadCNN
- Islamic State releases photo of alleged attackers in Russia shootingReuters