With concerns over security mounting, European airlines readied to bring home thousands of tourists from the Sinai peninsula resort of Sharm el-Sheikh, from where the crashed Russian plane took off last Saturday.
But there were angry scenes at the airport as thousands of anxious Britons who had hoped to fly home were sent back to their hotels after Egypt blocked additional repatriation flights.
In a sign of mounting fears about the security of baggage handling in Egypt, Dutch carrier KLM announced that it had banned check-in luggage on an early flight from Cairo, mirroring moves taken by several European airlines on Sharm flights.
The Islamic State (IS) jihadist group has claimed responsibility for the disaster, in which the Saint Petersburg-bound jet crashed minutes after taking off, killing all 224 mainly Russian tourists on board.
Cairo and Moscow have sought to downplay the suggestion of an attack.
But Obama told a US radio station, "I think there is a possibility that there was a bomb on board and we are taking that very seriously," while emphasising it was too early to say for sure.
In London, where Prime Minister David Cameron hosted Egyptian President Abdel Fattah al-Sisi yesterday, the British premier told reporters it was "more likely than not that it was a terrorist bomb" that caused the crash.
A joint intelligence operation used satellites to uncover the chatter between militants in Sinai and Syria, it said.


Latest News from World News Desk