Shocking pictures have emerged showing the devastating damage caused as bloodied passengers are seen lying badly hurt on the ground.
Russian President Vladimir Putin has offered his condolences to the victims, after the anti-terrorism committee confirmed ten people have died in the explosion.
Video shows terrified passengers running from the platform amid clouds of smoke.
One witness said: “I was riding down the escalator and suddenly an explosive wave from below, echoing from the tunnel.”
Another told Russia’s Life News: “People were bleeding, their hair burned. We were told to move to the exit, because the movement stopped.
“People just fled. My girlfriend was in the next car that exploded. She said that he began to shake.