The UN has published a map revealing which countries some three million Syrian refugees have fled to - with many escaping the conflict in Lebanon, Turkey and Jordan.
The UN refugee agency has said many newly arriving refugees only left Syria as a last resort.
A growing number, including more than half of those coming to Lebanon, have moved at least once before fleeing, and one in 10 have moved more than three times.
One woman told UNHCR she had moved 20 times before crossing into Lebanon.
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Scotland Yard said the male youths will appear in custody at Westminster Magistrates' Court on Saturday.
Windy this weekend with gales across northwestern parts of the UK. Rain spreading southeast.
Greater Manchester Police said "inquiries are ongoing to fully understand the circumstances of the incident."