At least 60 dead and 100 injured in attack at Crocus City Hall claimed by an Islamic State affiliate.
Deaths and injuries have been reported after a gun attack at a concert hall near Moscow, Russian media say.
At least four people dressed in camouflage opened fire at the Crocus City Hall, social media video verified by the BBC shows.
Video obtained by Reuters news agency shows a large blaze and smoke rising from the hall.
Russia's Foreign Ministry described the incident as a "terrorist attack". Specialist police are at the scene
Footage on social media showed gunmen inside the concert hall while state media reported that some people were still inside.
Tass news agency reported a third of the concert venue is on fire and the roof is almost completely ablaze.
Russian Foreign Ministry spokeswoman Maria Zakharova called on the international community to condemn the incident, which it called "a monstrous crime".
US National Security Council spokesman John Kirby said the images of the shooting were "horrible and hard to watch".
Putin was behind a series of apartment bombings when Yeltsin was president, thus making Yeltsin look weak. Yeltsin stepped down shortly after the bombings.
But now Putin is president, so whoever is behind this attack is making Putin look weak.
Unless a perpetrator is quickly identified and Putin sends the spetsnaz to get them. Then he will look like a strong leader who can defeat Russia's enemies.
It does make sense. People are resisting Violence and questioning Putin for being so brutal. By instilling Fear, he can legitimize his brutal response to everything that isn't the russian State.
Not behind literally every bad thing -true. But he does control everything that does happen in Russia. Nothing like this happens in Russia without some official support, or at least knowledge.
I'm not gonna beat up on Moscow for that one. Probably wasn't the best handling, but they had no incentive to mishandle it. It was a difficult hostage situation, and it could have also played out worse, as there were bombs in the theater.
It's hard to estimate an exact amount of gas that would incapacitate one person without killing someone else.
I'd like to think that we'd have done better than kill off a ton of the hostages in a similar situation, but we've also dicked up some hostage situations too, even where we've got lots of resources and time to plan.