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".
More top news
Over 2,000 People's Climate March protests have taken place in 166 countries ahead of a major UN conference on climate change.
On English votes for English laws Ed Miliband is damned if he does and damned if he doesn't.
School fees, pricey private medical care and the fear of interest rate rises mean even those on £200,000 are feeling the pinch.