By Alexey Eremenko, Tom Costello, Alexander Smith and Alastair Jamieson
MOSCOW — President Vladimir Putin suspended all flights to Egypt from Friday and ordered the repatriation of Russians from Sharm el-Sheikh amid the possibility that the crashed Metrojet airliner was brought down by a bomb.
The move followed advice from the head of Russia's security service who said it would be reasonable to halt flights until the cause of Saturday's crash was determined.
It came as the White House announced it is reviewing security at overseas airports for flights bound for the U.S.
British officials believe someone with access to the cargo hold placed an explosive device on the plane prior to take-off, the BBC reported Friday, while U.S. officials say terrorism remains a possible cause.
Pieces of wreckage have been sent to Moscow for testing, and analysts are looking for traces of explosives on Metrojet Flight 9268, which crashed Saturday on Egypt's Sinai Peninsula killing all 224 people on board.
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The British government suspended flights to and from Sharm el-Sheikh two days ago, but allowed airlines to resume return journeys Friday so stranded vacationers could return home.
These flights would be subject to "additional security measures," a government spokesman said in a statement, with passengers unable to check bags.
Budget U.K. airlines EasyJet and Monarch said dispatched empty airliners Friday to collect stranded vacationers, although some rescue flights were canceled due to restrictions by Egyptian authorities.
Dutch carrier KLM said its flight from Cairo to Amsterdam would be allowing only carry-on bags. "Based on national and international information, and out of precaution, KLM will not allow check-in luggage," the airline said.
One tourist told U.K. channel Sky News that security was so lax at Sharm el-Sheikh airport that he paid an official $35 to avoid luggage checks.
No U.S. airlines fly in to, out of, or over Egypt's Sinai Peninsula, where Sharm el-Sheikh is situated. But the crash could expose holes in security measures at overseas airports where U.S. airports do operate, security analysts and members of Congress said Thursday.
In total, 275 overseas airports have agreements with how they work with the Transportation Security Administration and the U.S. to enhance and ensure that the security complies with TSA regulations.
A handful of those airports, specifically those in the Middle East, will likely receive a mandate from the U.S. from to step up security. Measures could include enhanced random screenings or improvements to the screening of passengers, luggage or cargo.
More minor changes to airport security in the U.S. could including more random screening, more swabbing of hands for explosive residue and more canine teams in airports.
Alexander Smith and Alastair Jamieson reported from London.
Alexey Eremenko is a producer in NBC News’ Moscow bureau. He previously worked at Russia's sole English-language daily The Moscow Times and on the English desk of the RIA Novosti newswire. His main beats included politics, space and environment, and he has reported from Afghanistan, Mali, Iran and across Russia.
Tom Costello is an NBC News correspondent based in Washington, D.C.
Alexander Smith is a senior reporter for NBC News Digital based in London.
Alastair Jamieson is a London-based reporter, editor and homepage producer for NBC News.