Russia, Britain ramp up efforts to return stuck Egypt tourists

Moscow and London were ramping up efforts to pull out thousands of stranded tourists from Sharm el-Sheikh on Sunday, after Egypt said it was too early to know whether a bomb brought down a Russian plane.

Britain and the US, as well as international investigators, suspect a bomb exploded on board the Airbus minutes after it took off from the Red Sea resort en route to Saint Petersburg, killing all 224 people on board. 

Russia, which lost the most people in the disaster, has stopped all flights to Egypt and Britain has halted air travel to Sharm, while several other countries have warned their nationals not to fly to the resort due to security fears. 

Tens of thousands of people have been left stranded for days by the clampdown, which Egyptians fear could deal a heavy blow to their vital tourism industry, already battered by years of unrest.

Egypt has dismissed a claim from Islamic State jihadists that they brought down the plane, and on Saturday the head of its investigative committee said the cause of the crash was still not clear. 

"Initial observations... do not allow for identifying the origin of the in-flight break-up" of the aircraft 23 minutes and 14 seconds after it departed from Sharm, Ayman el-Mokkadem said.

"A noise was heard in the last second" on the voice recorder, he said, adding: "A spectral analysis will be carried out by specialised labs in order to identify the nature of this sound."

Egyptian Foreign Minister Sameh Shoukry said foreign intelligence that triggered the international travel restrictions had not been shared with Cairo.

Sources in France close to the investigation told AFP that black box data pointed to a bomb exploding and of the sudden, violent demise of the Airbus.

British Prime Minister David Cameron has said a bomb "had more likely than not" been the cause of the disaster.