The Islamic State militant group has executed 700 members of a tribe it has been battling in eastern Syria during the past two weeks, the majority of them civilians, a human rights monitoring group and activists said on Saturday.
The Syrian Observatory for Human Rights, which has tracked violence on all sides of the three-year conflict, said reliable sources had reported that beheadings were used to execute many of the al-Sheitaat tribe, which is native to Deir al-Zor province.
The conflict between Islamic State fighters and the al-Sheitaat tribe, who number about 70,000, flared after the militants took over two oil fields in July.