(VOVworld) - At least 10 people were killed in a blast on the St. Petersburg metro line Monday, state-run Russian news agencies said.

The train came to a stop at Technological Institute metro station in Saint Petersburg.

An explosion tore through a train as it was traveling between two stations in Russia's second-biggest city, injuring dozens. A second device was found and defused at another station, Russia's Anti-Terrorism Committee said. No group has claimed responsibility for the attack, which led to a shutdown of the city's metro system.
President Vladimir Putin, who had been in St. Petersburg earlier in the day, laid roses at a memorial with candles outside the bombed metro station. Russian Prime Minister Dmitry Medvedev described the explosion as a "terrorist act."

St.Peterburg authorities have declared 3 days of mourning.