The carnage was captured by photographers shortly after the blast. Scenes from the site of the explosion show bloody victims being wheeled into ambulances and others standing in shock outside the station. An image of the damaged train car shows a set of doors nearly blown off.
The explosive device detonated between the Sennaya Ploschad and Tekhnologichesky Institut stations at about 2:20 p.m. local time, according to the Associated Press. Terrorism is being probed as a possible cause.