St. Petersburg subway blast: At least 10 killed, security camera could hold clues

A bomb blast on a subway train in St. Petersburg, Russia, killed at least 10 people and wounded some 39 others Monday, Russian officials said, in what President Vladimir Putin called a possible act of terror.

One of the blasts came from a device that appeared to be filled with shrapnel, Sky News reported. Putin said investigators were looking into all possible causes. An unexploded device turned up at a different subway station as crews worked to deactivate it, anti-terror officials said.

A security camera spotted a man who may have left the bomb in a bag on the train, an unidentified source told the Interfax news agency without elaborating.

The explosive device blew up at 2:20 p.m. on a train that was leaving the Technology Institute station and heading to the Sennaya Square station, Russia's National Anti-Terrorist Committee said. Photos and video from Sennaya Square appeared to show wounded victims on the smoke-filled platform, and a train car with a door blown out. Frantic commuters reached out through the doors and windows, shouting, ''Call an ambulance!''

Nobody immediately claimed responsibility for the blast. Seven people died at the scene of the explosion, while one person died on the way to a hospital and two others died at the hospital, the country's health minister said.