An examination of passengers' personal belongings and luggage, along with fragments of the Russian airbus that crashed in North Sinai on 31 October, has revealed traces of explosives, Alexander Bortnikov, director of the Russian Federal Security Bureau (FSB), announced on Tuesday. He confirmed that an improvised explosive device, containing about a kilo of TNT, had been placed on the plane and it was this that caused the aircraft to break up in mid-air. “We can say with confidence that this was a terrorist act,” Bortnikov said. This, he added, “explains why the fragments were scattered over such a large area.” A source accompanying the FSB team involved in investigating the site of the airline disaster told Al-Ahram Weekly that the Russians arrived on Thursday 5 November and immediately began combing the 40-kilometre-square crash site. “It seems the team had drawn some important conclusions by the following morning, 6 November,” said the source. He suggested that it was after being informed of the team's findings that Russian President Vladimir Putin decided to halt Russian flights to Egypt. Egyptian reactions to FSB Director Bortnikov's announcement, which was not publicised until several hours after it was made, included expressions of condolences to the Russians and calls to include the bomb theory in the ongoing investigation into the cause of the crash and to tighten security measures at all Egyptian airports. “Egypt sympathises with the pain that the Russian people are feeling,” said Prime Minister Sherif Ismail. “The government has learned of the results of the Russian investigations and affirms that it will take them into account.” Speaking at a press conference in Sharm El-Sheikh on Tuesday evening, Ismail stressed that Egypt is cooperating with Russia in the fight to eliminate terrorism. At the same press conference, Minister of Civil Aviation Hossam Kamal said the investigative committees are proceeding in accordance with international law under which responsibility for announcing the results of the investigations falls to the lead Egyptian committee. Before Kamal spoke, a source at the Ministry of Civil Aviation revealed that Egyptian authorities had not been notified of any evidence uncovered by the FSB. Also in Sharm El-Sheikh, Minister of Interior General Magdi Abdel-Ghaffar stressed that airport security measures are being tightened. Screening of passengers and luggage has been intensified and routine inspections of all aircraft ramped up. Working teams have been set up to study the security ramifications of whatever conclusions the teams investigating the crash reach. General Mohamed Qashqoush, military advisor at the Regional Centre for Strategic Studies, said the Russian announcement of the cause of the crash of the Metrojet flight over Sinai raises a number of questions. The announcement was made unilaterally, without coordinating with Egypt, which heads the international team formed to investigate the crash. If the Russian announcement is correct, said Qahqoush, “then this means the Russians have uncovered tangible proof.” He continued, “If this is the case, then why was the Egyptian side not told? Why was the investigation team not notified?” On Egypt's responsibility for investigating the crash, Qashqoush said: “First, it is important for there to be a final report by the investigative committee. It is not possible to rely on a single party. There are other parties to the committee and they must agree on the same conclusion on the basis of material evidence.” There have been hints that Russia or other international parties might become involved in anti-terrorist operations in Sinai. Qashqoush dismissed the suggestion. “That would be difficult. Egypt has achieved considerable success in this area and it would not approve of any intervention,” said Qashqoush. “When Russia intervened in Syria, it announced it was doing so in response to a Syrian request. Sinai is under Egyptian sovereignty and Russian intervention there is out of the question.” The so-called Sinai Province, affiliated with Islamic State, has claimed responsibility for the Russian airplane crash. The announcement was initially greeted, in Egypt, with considerable scepticism.