A total of 530 people were killed in the first 23 days of the current truce in Syria, in areas covered by the cessation of hostilities agreement.
The Syrian Observatory for Human Rights says more than 1200 people died in areas not covered by the three-week-old ceasefire.
The partial truce - which excludes Islamic State and the al-Qaeda-linked Nusra Front - has been in place to allow peace talks to take place in Geneva between the government and opposition groups.
