An activist group says more than 2,100 people died in Syrian prisons last year and that many of the bodies showed signs of torture.
The British-based Syrian Observatory for Human Rights reported on Friday that 2,108 arrested people died in Syrian prisons in 2014. It said 27 people under the age of 18 and 11 women were among those who were killed.
The group said the death rates in prisons were the highest in the provinces of Homs and Rif Dimashq.
The Observatory urged U.N. Secretary-General Ban Ki-moon and the special U.N. envoy for the Syria conflict, Staffan de Mistura, to pressure the Syrian regime to release the 200,000 other detainees in Syrian jails, including political opponents and human rights activists.
Syrian officials could not be immediately reached for comment.