Russia and Egypt on Thursday dismissed suggestions by Britain and the United States that a bomb was likely to have brought down a Metrojet flight packed with Russian vacationers coming home from an Egyptian resort, saying the claim was premature. A spokesman for Russian President Vladimir Putin, Dmitry Peskov, insisted that aviation investigators were working on all possible theories as to why the Airbus A320-200 carrying 224 people crashed Saturday in Egypt's Sinai Peninsula, killing everyone on board. He said naming just one possibility was mere speculation.