Russian investigators confirm metro bomber as Akbarjon Djalilov

Russia's Investigative Committee on Tuesday named the attacker behind the Saint Petersburg metro blast as Akbarjon Djalilov, adding that he had also planted a second bomb that was defused by the authorities.

"The investigation identified the man who set off the bomb in the carriage of the Saint Petersburg metro. It was Akbarjon Djalilov," a statement by the committee said, adding that Djalilov's "genetic trace" was also found on a bag with the second bomb found at a different station.

Earlier on Tuesday, Kyrgyzstan security services named Djalilov as the "suicide bomber" behind the attack, adding he was a naturalised Russian citizen born in southern Kyrgyzstan in 1995.

On Tuesday morning, health minister Veronika Skvortsova said the death toll from the blast had climbed from 11 to 14 Tuesday as three people succumbed to their injuries, adding that 49 more people remained in hospital.

There was no immediate claim of responsibility for the explosion, which comes after the Islamic State group called for attacks on Russia in retribution for its military intervention in Syria against the extremists.

Pictures screened on national television showed the door of a train carriage blown out, as bloodied bodies lay strewn on a station platform.

Mourning

The Russian imperial capital began the first of its three days of mourning as tricolour flags flew at half mast throughout the city to honour the dead.

Flowers and candles piled up at an impromptu memorial outside the metro station hit by the attack as authorities beefed up security on the city's busy underground transport system.

Commuters began their daily trip to work under an anxious cloud after Monday's bombing that closed down the entire metro system that is seen as the lifeblood of the city.

"Everyone in the metro can only think of this," said 45-year-old Svetlana Golubeva as she entered the underground.

President Vladimir Putin, whose hometown is Saint Petersburg, offered his own condolences and later placed a bouquet of red flowers at the entrance to one of the stations, Technological Institute.

Russia has not been hit by an attack this deadly since the bombing of a plane carrying holidaymakers back to Saint Petersburg from the Egyptian resort of Sharm al-Sheikh in October 2015, which was claimed by IS. All 224 people onboard were killed.

Russian ground transport has also been hit by extremists before.

In 2013, twin suicide strikes within two days at the main railway station and a trolleybus in the southern city of Volgograd – formerly known as Stalingrad – claimed 34 lives and raised alarm over security at the Sochi Winter Olympic Games.

A suicide raid on Moscow's Domodedovo airport claimed by Islamic insurgents from the North Caucasus killed 37 people in January 2011.