but at the moment, the. >> emily: fis is on banning the flights and getting the 50,000 russians who are in egypt right now back home. it will be a bit logistical problem. >> matthew chance, thank you so much live from moscow. we should say the banning of flights from egypt, the dutch airline klm now says no luggage can be checked from cairo. this is the biggest country in the middle east, a major statement about the fears of security there, the fear of the rise of isis. the big question, of course, is what kind of bomb could have brought down the jet? miguel marquez has a special "outfront" report. >> reporter: finding a bomb that's already exploded in this? not an easy task. but one a thorough investigation should find. >> every one one of these bombings has a distinct signature. once you can put it together and link it back to a group or an individual, that's the ultimate goal here. >> reporter: for years, terrorists have sought new ways to bring down commercial jet aircraft, from bombs hidden in shoes to liquid containers, even