ST. PETERSBURG, Russia (AP/FOX 13) - The subway in the Russian city of St. Petersburg is reporting that 10 people are dead and at least 50 have been injured in an explosion on a subway train.
The subway's administration says all stations in the northern Russian city have been closed and that an evacuation is underway Monday afternoon.
Social media users posted photographs from one subway station in the city center, showing people lying on the floor and a train with a mangled door nearby.
Russian news agencies quoted Kremlin spokesman Dmitry Peskov saying that Russian President Vladimir Putin is visiting the city Monday and is expected to hold talks with the Belarusian president later in the day.
Putin said investigators are looking into the explosion as a possible terror attack and other theories about the deadly blast.
Moscow's deputy mayor announced that authorities will also be tightening security in the Moscow subway after the blast in St. Petersburg.
The Associated Press contributed to this report.