U.S., UK Say Bomb May Have Downed Russian Jet, Cairo and Moscow Dismiss Concerns

Britain probed security at Egypt's Sharm el-Sheikh airport on Thursday and scrambled to repatriate thousands of tourists as Cairo and Moscow dismissed fears a Russian plane was downed by a bomb.

Hours after Britain announced it was suspending flights in and out of the Red Sea resort, where most tourists are British or Russia, Germany's Lufthansa followed suit, citing "the current situation on the Sinai peninsula" as fears grew over airline safety. 

And several European governments said they were also reviewing the situation.

British Prime Minister David Cameron held an emergency cabinet meeting on the repatriations and spoke to Russian President Vladimir Putin to explain the decision before talks with Egyptian President Abdel Fattah al-Sisi at Downing Street.

Citing intelligence, Cameron said it was "more likely than not that it was a terrorist bomb" that had caused a Russian passenger jet to crash in the Sinai Peninsula on Saturday.

"There are a relatively simple and straightforward set of things that need to happen at Sharm el-Sheikh airport to give us greater certainty of safety," he added.

Flight KGL9268, which was heading for Saint Petersburg, crashed soon after takeoff from Sharm el-Sheikh airport, killing all 224 people on board.

Washington also believes a bomb may have caused the crash, but Cairo and Moscow contradicted that assessment.

A U.S. official familiar with the matter told CNN on Wednesday that the latest U.S. intelligence suggests that the crash was most likely caused by a bomb on the plane planted by the Islamic State group or an IS affiliate.

The official stressed that there has not been a formal conclusion reached by the U.S. intelligence community. "There is a definite feeling it was an explosive device planted in luggage or somewhere on the plane," the official said.

The assessment was reached, the official added, by looking back at intelligence reports that had been gathered before Saturday's plane crash and intelligence gathered since then. The United States did not have credible or verified intelligence of a specific threat prior to the crash, however, the official said, prior to the incident, "there had been additional activity in Sinai that had caught our attention."

Another U.S. official said the intelligence regarding the IS is in part based on monitoring of internal messages of the extremist group. Those messages are separate from public IS claims of responsibility, that official said.

Egypt's civil aviation minister Hossam Kamal said Thursday that investigators "have as yet no evidence or data confirming the theory" of a bomb attack.

And the Kremlin dismissed the idea as "speculation."

"The reasons for what happened can only be put forward by the investigation," said Kremlin spokesman Dmitry Peskov.

"Any other proposed explanations seem like unverified information or some sort of speculation."

- Sisi, Cameron in talks -

On Thursday, Cameron welcomed the Egyptian president to Downing Street on a pre-planned trip -- his first visit to Britain since the overthrow of his predecessor Mohamed Morsi in 2013.

Around 200 protestors staged a demonstration against Sisi's human rights record, some temporarily blocking the entrance to Downing Street.

Foreign Secretary Philip Hammond said Britain was planning emergency measures to repatriate holidaymakers from Sharm el-Sheikh, starting from Friday.

There are an estimated 20,000 Britons currently at the Red Sea resort.

Hammond said the measures "will allow us to screen everything going onto those planes, double-check those planes so we can be confident that they can fly back safely to the UK."

A small British military team has been sent to the resort as part of the review.

Egyptian Foreign Minister Sameh Shoukry told CNN television it was "somewhat premature" to reach conclusions and suspend flights.

But Hammond said Shoukry "hasn't seen all the information that we have."

The Islamic State jihadist group claims it caused the crash and said Wednesday it would reveal how at a time of its choosing.

The Russian jet was flying at altitude of 30,000 feet (9,150 meters) when it lost contact with authorities, 23 minutes after take-off.

Experts say the fact that debris and bodies were strewn over a wide area points indicated the aircraft disintegrated in mid-air, meaning the crash was likely caused by either a technical fault or a bomb on board.

If confirmed, it would be the first time Islamic State, which controls large areas of Syria and Iraq, has bombed a passenger plane.

The IS affiliate in Egypt is waging a bloody insurgency in north Sinai that has killed hundreds of policemen and soldiers.

- Egypt tourism threatened -

The crash has sparked fears in Egypt over its vital tourism sector on the peninsula.

A string of major tour operators have suspended package flights to its resorts, while analysts have warned the industry faces serious risk of lasting damage.

"Tourism in Egypt will simply die if it was a terrorist attack that brought the plane down," said Hamada Nagi, a tour operator from the Red Sea resort of Hurgada.

Russia on Thursday began burying the first victims of the crash, with several hundred people gathering in Veliky Novgorod, south of Saint Petersburg.

Russian air force commander Viktor Bondarev also said Moscow had sent anti-aircraft missile systems to Syria to back up its air campaign in order to counter "every possible threat."

"Let's imagine a military plane is hijacked and taken to a neighboring country and air strikes are aimed at us. And we have to be ready for this," Komsomolskaya Pravda newspaper quoted him as saying.