The Syrian government has likely used chlorine gas to attack civilians while the Islamic State group, also known as ISIS, has committed crimes against humanity with attacks on civilians in two provinces in the country, an independent U.N. commission said Wednesday.
The report from the commission, which has been tasked to investigate potential war crimes in the country, warns that the alarming number of foreign fighters and their extremist allies in Syria, including ISIS, have raised the violence to levels that threaten the overall region. Civilians, including children, are encouraged to watch public executions, amputations and lashings organized by Islamists, the report found.
The U.N. Security Council is scheduled to meet Thursday to discuss the report. Nearly 200,000 people have died since civil war engulfed the country.
The report marks the first time the United Nations has assigned blame for the use of the chemical agent. Specifically, the commission said "reasonable grounds exist to believe" that government forces loyal to President Bashar Assad unleashed a chemical agent, likely chlorine, on civilians in northern Syrian villages eight times in April.
According to the report, victims and medical personnel described symptoms caused by exposure to chemicals and witnesses told of a chlorine-like smell immediately after seeing government helicopters drop barrel bombs on the civilian-inhabited areas in Idlib and Hama provinces eight times between the 11th and 29th of April.
The use of chemical weapons is considered a war crime under international law.
The commission also noted widespread and systematic civilian killings by Islamic State, which now controls a swath of north and eastern Syria. It said attacks have taken place in the northern province of Aleppo and in the northeastern region of Raqqa, a stronghold of the group. The findings mean that U.N. officials now believe Islamic State has committed crimes against humanity in Syria and Iraq, the two countries in which the group has carved out a self-styled caliphate.
"This is a continuation — and a geographic expansion — of the widespread and systematic attack on the civilian population," according to the report by the four-member commission chaired by Brazilian diplomat and scholar Paulo Sergio Pinheiro.
The group's gruesome beheading of American journalist James Foley and its declaration of a state governed by a harsh interpretation of Islamic law across Iraq and Syria have inserted a new dynamic into the international standoff over the Syrian war.
The latest report, based on 480 interviews and documentary material, cited dozens of documented public executions in Aleppo and Raqqa during the bloody and complex Syrian civil war that the United Nations says has killed more than 190,000 people.
Crowds of people including children have reportedly watched as the group's fighters pronounce mostly adult men guilty of violating religious laws, and then behead them or shoot them in the head at close range. The purpose, according to the commission, is "to instill terror among the population, ensuring submission to its authority."
Photos posted online Wednesday show the aftermath of the Islamic State group's takeover of the Tabqa air base in Raqqa province. In one photo, masked gunmen can be seen shooting seven men kneeling on the ground in front of them.
The photos correspond to other reporting by The Associated Press of the airfield's fall to the extremist militants.
But the commission also emphasized that Assad's government forces continue to perpetrate crimes against humanity — the most serious and systematic type of widespread crime against civilians— through massacres and systematic murder, torture, rape and disappearances. And it said other factions fighting Assad's government are also committing massacres and war crimes.
On Monday, U..N. High Commissioner for Human Rights Navi Pillay said the Islamic State fighters reportedly killed up to 670 prisoners in the Iraqi city of Mosul and committed other horrific abuses that amount to crimes against humanity.
Pillay said the Islamic State group and other fighters allied with it are daily committing "grave, horrific human rights violations" in Iraq such as targeted killings, abductions, trafficking, slavery and sexual abuse in an aggressive push to gain a firm grip on Iraq's northern and eastern provinces.
Fox News' Jonathan Wachtel and The Associated Press contributed to this report.