Developing news tonight.

The death toll from the terrorist attack on a concert hall in Russia has surpassed 130.

Officials fear the grim number of victims gunned down will almost certainly rise.

First responders are still combing through the smoldering ruins of the hall that the attackers also set on fire.

And the Russian President Mr. Putin says that those responsible for the act of terrorism have already been captured.

Rachel Menitoff joining us live from The New Center tonight. She's got details on that. Rachael.

Russian President Vladimir Putin speaking publicly today called this a barbaric act of terrorism and vows to punish the attackers.

Russia arrested 11 people, including four gunmen suspected of carrying out the attack.

The terror group ISIS is taking responsibility.

And a US intelligence official told the associated press [that] it has confirmed this claim.

Mourners light candles outside of the Russian embassy in memory of the victims killed in a deadly terrorist attack at a popular concert venue in Russia's capital.

The death toll has risen to more than 100 people killed and hundreds are wounded as investigators comb through the charred wreckage for more victims.

This woman, Margarita Bunova, was inside the venue when men dressed in camouflage reportedly used assault rifles to spray the crowds with gunfire and tossed explosives which quickly set the scene on fire.

Bunova's husband grabbed her and they fled through an upper-level fire escape.

She says, "When I came home, I hugged my children," and said, "It simply cannot be conveyed in words. They were shooting at us. I started to go hysterical and panic."

The violence erupted days after President Vladimir Putin won re-election in what's being called a highly orchestrated electoral landslide.

In his address to the nation Saturday, Putin says all four direct perpetrators were found and detained.

He says Russian authorities captured the suspected gunmen as they were trying to escape into Ukraine through a window prepared for them on the border.

Kyiv firmly denies the allegation and ISIS claimed responsibility.

The US is warning Americans abroad to stay put and remain plugged into any official updates.

Hopefully, we saw our State Department or embassy there put out a notice to all Americans in Moscow to avoid any large gathering, concerts, obviously, shopping malls, anything like that, just for their own safety.

The White House confirms the US government actually warned Russia that ISIS militants were planning to target them, but Mr. Putin shrugged it off, even calling it blackmail.

He's declared tomorrow as a national day of mourning and said more security measures have been added throughout the country.

That's the latest from The New Center. I'm Rachel Menitoff. Rick, back to you.

Alright, Rachel, thank you for that.