Russia has identified groups behind plane explosion in Egypt, security chief says
Explosion killed all 224 passengers on board in October.
Egypt's Prime Minister Sherif Ismail (4rth R) at the remines of a plane crash at the desert in central Sinai near El Arish city north of Egypt, October 31, 2015(photo credit: (AICF/CHRIS LEE))ByREUTERSUpdated: