ISIS has killed 1,878 people in Syria—most of them civilians—over the six-month period since it proclaimed a caliphate in parts of Iraq and Syria in late June, according to the Syrian Observatory for Human Rights. Among the victims: four children, eight women, members of an opposing Sunni Muslim tribe, soldiers of Syrian President Bashar al-Assad, insurgents fighting against Assad, foreign activists and journalists, and even about 120 of its own fighters. Although Reuters says it hasn't been able to independently confirm the British organization's numbers, it notes the publicized stonings and beheadings that ISIS has conducted for what it sees as offenses against Islam, ranging from adultery and homosexuality to blasphemy and stealing.
By the monitor's count, 1,175 civilians have been beheaded, stoned, or shot; about 930 of those civilians were part of the Shaitat, a Sunni Muslim tribe that fought ISIS in eastern Syria. A mass grave containing 230 Shaitat bodies was said to have been discovered in mid-December, Al Arabiya reports. But the tally may even be on the low side, Al Arabiya notes: The observatory references "hundreds of missing and detainees inside the IS jails, loss of communication with about a thousand men of al-Shaitaat tribe, [and] ... dozens of Kurds who have still been missing since ... September 16." (A recent ISIS execution video is said to have major differences from past videos.)