"ISIL (IS) has established unlawful, so-called 'shari'a courts' in the territory under its control that have been meting out cruel and inhuman punishments to men, women and children accused of violating the group's extremist interpretations of Islamic shari'a law or for suspected disloyalty," Ravina Shamdasani said, in a statement published on the OHCHR website.
According to Shamdasani, the jihadist group posted photographs of men being crucified after being sentenced for banditry. Shamdasani also mentioned men thrown off buildings following convictions of homosexuality.
The organization also received reports of numerous executions of women. "Educated, professional women, particularly women who have run as candidates in elections for public office seem to be particularly at risk," Shamadasani noted. Three female lawyers have reportedly been executed in the first two weeks of 2015.
The Islamic State is a jihadist group that has taken areas of Iraq and Syria under its control. Notorious for multiple human rights abuses, the insurgents have kidnapped large numbers of people, including military personnel and journalists. Last year, the group posted several videos of executions of journalists and aid workers.