Transcript for Subway terror attack rocks Moscow

next nominee confirmed as well. Jonathan Karl, thanks, Jon. Is. The deadly terror attack in the subway in St. Petersburg, Russia, and tonight new report of a second bomb discovered. The first device ripping through a subway car, passengers staggering. And the video right after. Here is the question, who is behind it. Here is chief investigative correspondent Brian Ross. Reporter: The chaos and carnage today on a Russian subway platform are what law enforcement officials around the world fear could happen in their city. Heavy smoke. The mangled door of a subway car. People crying for help. At least 11 people were killed, their bodies pulled out of the wreckage. This bloodied woman was one of some 40 other passengers wounded in the blast, all from a single bomb that went off as the train travelled between two stations in mid-afternoon. Less than an hour later, officials discovered and disarmed a second bomb, in this black bag, loaded with shrapnel, planted at another St. Petersburg subway station. It all happened in Russia's most-westernized city, until now free from terror attacks, on the same day that Russian president Vladimir Putin arrived in St. Petersburg as part of his re-election campaign. Putin said it was too early to say who is responsible but Russian experts say it's clearly meant to send him a message. Regardless, they knew that Putin was going to be in town and they targeted the metro, the easiest way to make sure that the largest number of people in that city know there's a problem. They likely knew Putin is in town. Any clues who might be responsible? There is no claim of responsibility but there is no shortage of suspects either, including ISIS and chechen extremist grums. Brian Ross, thank you. We turn next to the severe

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