Two female suicide bombers blew themselves up in Moscow subway trains during Monday morning rush hour. The first blast, at 7:56 a.m. local time, killed 24 people as a train was stopped at the central Lubyanka station, which is where Russia’s Federal Security Service intelligence agency has offices. The second blast came 40 minutes later on a train at Park Kultury station; a woman wearing a plastic-explosives-packed belt detonated herself as the train doors opened, killing 14. Over 100 were injured by both blasts. No one has claimed responsibility for the attack, though earlier suicide attacks have been carried out by Islamist rebels who want independence in Chechnya. Last month, the Chechen rebel leader promised, "the zone of military operations will be extended to the territory of Russia... the war is coming to their cities.” The motives of the women who carried out the attacks are not yet clear, but Russia has long feared Chechnyan women who call themselves "Black Widows" and carry out suicide bombings to avenge family members killed in the Chechnyan wars of the 1990s.