Russia hunts for 'black widow' suspects ahead of Sochi games
Video duration: 2:16
In Sochi, Russia, the site of the 2014 Winter Olympics, the images of three women were posted around the city. Known as "black widows," the suspects are believed to be potential suicide bombers, intent on attacking the games. Hari Sreenivasan looks at recent bombings in the region and how Russia and the U.S. are reacting.