Russian security services : 3 members of team behind subway attack killed . Two female attackers detonated their explosives about 40 minutes apart . Blasts ripped through Lubyanka and Park Kultury stations in Moscow , killing 40 .
Russian security officials : 3 members of group behind subway bombs killed . Two female bombers detonated their explosives about 40 minutes apart . Blasts ripped through Lubyanka and Park Kultury stations in Moscow , killing 40 .