A bomb blast has torn through a subway train deep under Russia’s second-largest city, killing 11 people and wounding more than 40 in a chaotic scene that left victims sprawled on a smoky platform. Hours later, anguish and fear rose again when police found and defused a shrapnel-packed explosive device at another St. Petersburg station.

There were no immediate claim of responsibility for the attack, while President Vladimir Putin was visiting the city, his hometown. In the past two decades, Russian trains and planes have been frequent targets of terrorism, usually by Islamic militants.

"Law enforcement agencies and intelligence services are doing their best to establish the cause and give a full picture of what happened," a somber-looking Putin said.

The National Anti-Terrorism Committee said it was looking for the “perpetrators and organizers of the terror attack.”

“From now on, I will be scared to take the subway,” said Marina Ilyina, 30, who brought flowers to the station where the train stopped after the bombing. “We in St. Petersburg thought we wouldn’t be touched by that.”

“Everything was covered in smoke. There were a lot of firefighters,” Maria Smirnova, a student on a train behind the stricken one, told independent TV station Dozhd.

“They won’t succeed in breaking up our country. We are all citizens of one country despite various political views and religious beliefs,” said 24-year-old Alexander Malikov, who brought flowers and candles to an improvised memorial outside one of the stations.

By Premji