Foreign Secretary William Hague said a report by Human Rights Watch that identified torture and atrocities in Syria sounded a clear warning that there was "no hiding place" for those responsible for such crimes.
The rights organisation has carried out more than 200 interviews since the beginning of anti-government demonstrations in the country in March last year.
Accounts from former detainees and defectors have identified the locations, agencies responsible, torture methods used and, in many cases, the commanders in charge of 27 detention facilities run by Syrian intelligence agencies.
Human Rights Watch said the systematic patterns of ill-treatment and torture it had documented clearly pointed to a "state policy of torture and ill-treatment", which constituted "a crime against humanity".
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The boy was found unconscious and in cardiac arrest and was rushed to hospital where he died.
The victim, who was wearing her uniform at the time, was found knocking on doors nearly four hours after she was abducted.
There will be gales across Scotland and northern England this morning, but these will gradually ease through the afternoon.