Germany's Lufthansa Group said it's suspending all flights to and from Egypt's Sharm El-Sheikh "due to the current situation on the Sinai Peninsula, following the crash of a Russian plane in Egypt that killed all 224 people onboard last Saturday The airline said Thursday that two weekly flights of subsidiaries Edelweiss and Eurowings would be affected. It says it will work with the German Foreign Ministry and trip organizers to make sure that any passengers already in Sharm El-Sheikh are safely returned home. The Foreign Ministry told The Associated Press there are currently 50 Germans known to be in the resort area. Other Lufthansa Group airlines have already changed routes so as to fly around Sinai. Lufthansa says flights to Cairo will not be affected by any of the new measures. British Transport Secretary Patrick McLoughlin, meanwhile, said Egypt will have to put in place tighter long-term airport security measures before British flights resume to the Sinai Peninsula. McLoughlin told the House of Commons Thursday that British security teams had been sent to Sharm El-Sheikh and "will be working intensively with the Egyptian authorities to allow normal scheduled operations to recommence." The UK grounded all flights to and from Egypt's Sinai Peninsula Wednesday, saying there was a "significant possibility" a Russian airliner that crashed Saturday was downed by a bomb. McLoughlin said short-term measures, including different luggage-handing arrangements, would allow the estimated 20,000 British nationals in the Sharm El-Sheikh area to fly home. In the longer term, he said Britain would "need to be confident" there was strong security in place before scheduled flights could resume. British Prime Minister David Cameron also said that the British "don't know for certain that it was a terrorist bomb" that caused the Russian plane crash in Egypt last weekend. Cameron spoke Thursday, shortly before a meeting with Egypt's president. He said, "There's still an investigation taking place in Egypt. We need to see the results of that investigation." He said the British decision to suspend flights was based on "intelligence and information we had that gave us the concern that it was more likely than not a terrorist bomb." He said that Britain wants "to start as soon as possible" to bring tourists home, and empty planes will be flying out from Britain to bring people back. But Cameron cautioned that it would take "some time" to bring everyone back. Cameron a;so said the crash of a Russian jet in Egypt was "more likely than not" caused by a bomb. He saaid he would call Russian President Vladimir Putin later in the day to discuss the crash. Egypt's Foreign Ministry spokesman Ahmed Abouzeid said Britain's decision to suspend flights to Sharm El-Sheikh was taken unilaterally without consulting Cairo. In a statement, Abouzeid says Egypt and the UK had high-level communication just hours before Britain's decision. He added that Egypt has reacted positively to British concerns and has bolstered airport security. He also says that this does not mean that Egypt views airport security as the cause of the plane crash. Russia's top aviation official says investigators examining potential causes of the plane crash over Egypt will look for traces of explosives on the wreckage. Alexander Neradko also called for caution in publicizing speculation about the likely causes of the crash, saying investigators are considering all theories — including a terrorist attack. Both Russia and Egypt on Thursday dismissed suggestions by Britain and the United States that a bomb was likely to have brought down the Metrojet flight, packed with Russian vacationers coming home from the Egyptian resort of Sharm El-Sheikh. — AP