(UPDATE) MOSCOW: Assailants burst into a large concert hall in Moscow on Friday and sprayed the crowd with gunfire, killing over 60 people, injuring more than 100 and setting fire to the venue in a brazen attack just days after President Vladimir Putin cemented his grip on power in a highly orchestrated electoral landslide.

The Islamic State group claimed responsibility for the attack in a statement posted on affiliated channels on social media. A US intelligence official told The Associated Press that US intelligence agencies had learned the group's branch in Afghanistan was planning an attack in Moscow and shared the information with Russian officials.