Russia's Investigative Committee has named the attacker behind St 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 St 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.


The Russian imperial capital was beginning the first of three days of mourning and Russian 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 tightened 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.


The blast occurred in a train carriage as it was travelling between the Technological Institute and Vosstaniya Square stations at 2:40 pm (local time), said anti-terrorist committee (NAK) spokesman Andrei Przhezdomsky

Source: NNA