The scene of the crash. (AAP)  Moscow has acknowledged for the first time a terrorist attack could have caused last month's Russian plane crash in Egypt, as thousands more tourists were evacuated from the country.  Britain and the US, as well as international investigators, suspect a bomb exploded on board the Metrojet A-321 plane, but Egyptian officials insist there is no evidence yet of an attack on the aircraft which jihadists claim to have downed.  Russia had also previously refrained from blaming the crash, which killed all 224 people on board, on terrorists until Prime Minister Dmitry Medvedev's admission.  "The possibility of an act of terror is of course there as the reason for what happened," Medvedev said in an interview with Rossiyskaya Gazeta state newspaper.  A growing international chorus has backed the theory that the plane was downed in an attack, with British Foreign Minister Philip Hammond saying Monday it was "more likely than not" that the plane was downed by an "explosive device placed on board".  On Monday, Israel - which has strong intelligence links to neighbouring Sinai where the Airbus came down while en route from Egypt's resort of Sharm el-Sheikh to Saint Petersburg - joined in.  All 224 people aboard the flight died. (AAP)  "There is a strong probability that this is an attack," Defence Minister Moshe Yaalon told Israeli reporters on Monday.  And Airbus chief Fabrice Bregier said no technical fault has yet been detected for the crash of the A-321.  "I can say that so far, what we got from the investigation didn't trigger any action, technical action on our side, regarding the A-321 fleet," said Bregier.  Russia has declared a day of mourning for the victims. (AAP)  "But we need to wait for the conclusion of the investigations."  Amid the tourist exodus from Egypt, a senior operative of the Islamic State jihadist group, Ashraf Ali Ali Hassanein al-Gharabli, was shot dead in an exchange of fire in Cairo after police tried to arrest him, the interior ministry said.  The IS group's branch in the Sinai claimed responsibility after the Russian plane crash.  IS said it downed the plane in retaliation for Russian air strikes in Syria, but has not said how.  Meanwhile, tens of thousands of foreign tourists, including some 80,000 Russians and 20,000 Britons, were stranded in Egypt after flights were cancelled over security fears.  Russian President Vladimir Putin on Friday suspended all flights to Egypt.  Moscow said on Monday that about 25,000 Russian tourists had so far returned on more than 100 flights, while London said some 5,000 Britons had returned home.  Hammond said he hoped flights to Sharm could resume soon, once "robust" security arrangements are in place.
A terrorist attack may have downed a Russian plane in Egypt's Sinai Peninsula, Russia's Prime Minister Dmitry Medvedev has admitted.