Monday's explosion occurred as the train traveled between stations on one of the city's north-south lines.
The blast happened when the train was between the Sennaya Ploschad and Tekhnologichesky Institute subway stations.The second device was found at Ploshchad Vosstaniya station. The chief of the Saint Petersburg metro, Vladimir Garyugin, said Tuesday that quick actions by metro staff prevented a much higher toll and that passengers had helped each other instead of panicking. Forty-nine wounded were still hospitalized, she said.
Meanwhile, commuters travelled to work under an anxious cloud after Monday's bombing, which forced the entire metro system - seen as the lifeblood of the city - to shut down temporarily. Maxim Liksutov, Moscow's deputy mayor, said that included tightening security on the subway in the Russian capital.
Jalilov has been registered at an apartment in the north of St Petersburg since 2011, according to a source in the Russian authorities, and he has a Daewoo Nexia vehicle registered in his name.
Details are still coming out about who was behind the bomb.
"Regarding the link with Islamic radicalism, we have to wait to know more until the investigation yields its full results", Abyldaev said at a press conference with Russian Foreign Minister Sergey Lavrov.
There was no immediate claim of responsibility for the blast.
Russia's Investigative Committee has named the man who detonated the bomb on a St. Petersburg metro train on Monday afternoon.
How has the world responded?
His spokesman, Dmitry Peskov, told reporters on Tuesday the fact the Russian president was in the city when the bomb went off, though several dozen miles away from where he was hosting talks, "makes one pause" and is "something for the intelligence agencies to analyse".
He visited the scene on Monday evening and laid flowers at a makeshift shrine.
The bombing raised jitters coming just over a year before Russian Federation is due to host the Football World Cup in venues including Saint Petersburg.
President Pranab Mukherjee on Tuesday said the blast in St. Petersburg is a reminder that terrorism must be dealt with "urgently and comprehensively". "We have had explosions before and I think these instructions are very clever, very correct". "The terrorists will not win".
"On behalf of the government of Israel, I send condolences to President Putin and to the families of those who were murdered, following today's bombing on the St. Petersburg subway", Netanyahu said in a statement.
What should I do if I'm anxious? Progress in this field is of equal importance to individual enterprises of Belarus and Russian Federation and to the countries in general as it will help them boost their trade.
If you're feeling anxious then it's best to talk to someone you trust, like a parent or teacher.