Russia's state investigative committee on Tuesday named Akbarzhon Jalilov as the man behind the St Petersburg metro blast, confirming an earlier statement from Kyrgyzstan's security services.

The committee said in a statement its investigation had identified Jalilov, whose genetic traces were also found on a bag containing an explosive device.

"From the genetic evidence and the surveillance cameras there is reason to believe that the person behind the terrorist act in the train carriage, was the same one who left a bag with an explosive device at the Ploshchad Vosstaniya station," the statement added.

The blast on Monday has killed 14 people so far and injured almost 50.