Top Russian agency investigating assault on concert hall as a terrorist attack

Russia's top investigative agency is investigating the shootings, explosions and fire at a Moscow concert hall as a terrorist attack.

The Investigative Committee said it has opened a criminal probe into the charges, though it didn't say who might be behind the attack.

Several gunmen burst into a big concert hall on the edge of Moscow on Friday and sprayed visitors with automatic gunfire, killing and injuring an unspecified number of people and starting a massive blaze.

The attack happened just days after President Vladimir Putin cemented his grip on the country in a highly orchestrated electoral landslide.