SHARM EL-SHEIK , Egypt, Nov. 6 (UPI) -- Russia has suspended all flights to Egypt after investigators revealed they believe a bomb caused the crash of Metrojet Flight 9268 last weekend -- adding to the already tens of thousands of travelers still stranded in the Sinai Peninsula.
Russian President Vladimir Putin made the announcement after intelligence officials said they believe a bomb was placed into the checked luggage hold of the Russian airliner that crashed in Egypt's Sinai Peninsula. The crash has prompted U.S. authorities to review passenger screening at overseas airports.
Multiple international airlines departing Egypt said only carry-on luggage would be permitted as further evidence points to the theory a bomb downed Metrojet Flight 9268, killing all 224 people aboard.
Authorities in Britain believe someone with access to the cargo hold -- possibly a ground crew member or baggage handler -- placed a bomb on the plane prior to takeoff at the Sharm el-Sheikh International Airport. The plane was headed toward St. Petersburg, Russia.
Although no U.S. airlines operate at Sharm el-Sheikh Airport, and must fly above 26,000 feet over the Sinai Peninsula, the crash could expose security lapses in overseas airports where American carriers do have a presence.
"While it hasn't been confirmed officially, there are intelligence reports that it is likely that this could have been a bomb placed on the airplane by [the Islamic State], and that is our grave concern at this point in time," Rep. Michael McCaul, R-Texas, chairman of the House Homeland Security Committee, said Thursday.
Although a technical failure has not been ruled out as the cause, that explanation is beginning to seem more unlikely to authorities. Russia and Egypt said they will not speculate on the cause until the conclusion of the official investigation.
The Islamic State affiliate Sinai Province said they destroyed the plane but did not specify how. The militant Islamist group was previously known as Ansar Beit al-Maqdis before pledging allegiance to IS leader Abu Bakr al-Baghdadi.
Sinai Province has launched continued attacks since former Egyptian President Mohamed Morsi was ousted in 2013. The group claimed responsibility for an attack in the peninsula that killed about 30 people in January.
As a result of numerous flight cancellations, tens of thousands of passengers have been left stranded in Sharm el-Sheikh -- unable to return home after London scrapped all air service to the African nation.
Officials said about 20,000 British citizens and as many as 40,000 Russians have been stranded there since Wednesday.
British carrier easyJet said Egyptian authorities scrapped eight of its 10 scheduled flights Friday. Further, the African nation's aviation minister said 21 of the 29 total scheduled flights from Sharm el-Sheikh to the U.K. Friday were canceled.
"We are continuing to work with the Egyptian authorities and the UK government to get our customers back home as soon as possible," easyJet said in a statement Friday. "We continue to work on a contingency plan so we can operate as soon as we receive permission to fly."
It appears that many of the stranded Britons will have to spend at least a few more days stranded in Egypt, USA Today reported.
Some visitors are getting creative with their travel plans -- driving from Sharm el-Sheikh to Cairo, where they hope to board a flight home.
"If people from Wednesday haven't left yet, how am I going to leave tomorrow?" asked Briton Joseph Day, whose flight was canceled Friday. "We know nothing, the airlines have been absolutely useless."
"We don't know what and why. Obviously, it's not security anymore because they are letting planes land," said passenger Carla Dublin, who later asked Britain's ambassador to Egypt, John Casson, about a rumor she'd heard that five flights to get stranded passengers home were arranged -- then scrapped by the British government.
She received no answer.
"Something happened between David Cameron and the government overnight," Dublin had said in her inquiry to Casson.
"The last few days have actually been quite precarious in terms of the information we have been receiving. I have just been spending time with my father. He had a heart attack last Friday," passenger Leon Chlon told BBC News.
"We felt as though we were on our own. We all got together really. There was a lot of camaraderie. At the airport today it was absolutely dreadful," traveler Nicky Bull remarked.
As a result of the investigation, which examines the possibility that a bomb was smuggled on Flight 9268 in luggage, many carriers are not allowing passengers to board with baggage. British officials said they are working to ensure that returning passengers receive their luggage within a week to 10 days.