The Metrojet Airbus A321-200 broke up mid-air on Saturday shortly after takeoff from the Egyptian resort of Sharm el-Sheikh to St Petersburg, scattering fragments of wreckage over a wide area in Sinai (left). Terrorism and aviation experts believe a bomb is the only likely explanation, citing the fact there was no distress call from the pilots and that some wreckage shows the fuselage skin peeling outwards (inset) possibly due to a 'force acting outwards from within'. Alexander Smirnov, the deputy general director of Metrojet's parent company Kogalymavia, also told a news conference in Moscow today that the cause of the crash 'could only have been a mechanical impact on the plane' in the air.