BREAKING! St Petersburg metro explosions, At least 10 dead after blast on Russian subway(GRAPHIC)

At least 10 people have been killed and 50 more injured in explosions in the St Petersburg metro system.



There were blasts in two metro carriages at two stations, St Petersburg emergency services said.



News agency Interfax cited a source as saying at least one of the blasts involved a device filled with shrapnel.



The agency cited the governor's press office saying 50 had been injured.



A Reuters witness saw eight ambulances near the Sennaya Ploshchad metro station while local media reported the nearby Institute of Technology station was also affected.



Russia's anti-terrorism committee confirmed at least 10 people had been killed.



All metro stations in St Petersburg have been closed, Interfax reported, citing metro staff.



Investigators are looking into a possible terror attack and other theories for the St Petersburg subway blast, Mr Putin said.



He was visiting the city and was expected to hold talks with the Belarusian president later in the day.



The Russian President expressed his condolences to the families of the victims.



The Moscow metro has increased its security after the blasts in St Petersburg.



"The Moscow metro is taking up additional security measures in the framework of the federal law on Russia’s transport security," a statement posted Telegram said.



"Authorities of the Moscow metro are ready to provide any assistance to the St Petersburg metro if needed."