The United Nations on Wednesday accused Islamic State fighters of committing war crimes, including public executions in the presence of children, and said it believed the Syrian government had used chlorine gas in combating its enemies.
A report by the United Nations Human Rights Council, based on nearly 500 interviews and evidence collected between late-January and mid-July of this year, said that both government forces and non-state armed groups had committed war crimes, including murder, torture, rape and sexual violence as well as using children in the hostilities and targeting civilians.
“As fighting has engulfed civilian areas, the barest possibility of a normal life has been destroyed,” the report said. “The impact has been particularly grave for women and children, whose most basic rights are infringed by the conduct of the parties.”
The report said that “reasonable ground exists to believe that chemical agents, likely chlorine,” were used by Syrian government forces in eight incidents within a 10-day period in April in the villages of Kafr Zeita, Al-Tamana’a and Tal Minnis.
There were also cases of rape and sexual assault of women detailed at detention facilities in the capital Damascus by government forces, which the report said had “perpetrated rape as a war crime.”
Islamic State (IS) fighters, according to the report, had issued beatings and lashings for smoking, possessing alcohol and to women who appeared in public “improperly dressed.”
“In some cases, victims were tied to a wooden board or crucifix and displayed publicly in the squares before being lashed,” the report said.
The reports come amid reports on Wednesday that IS members executed Syrian army soldiers and are holding a group hostage after capturing an air base in northeast Syria over the weekend.
IS had stormed Tabqa air base near Raqqa city on Sunday after days of fighting with the army that cost more than 500 lives, according to the Syrian Observatory for Human Rights (SOHR), a UK-based group opposed to the regime of President Bashar al-Assad.
Tabqa was the army's last foothold in an area otherwise controlled by the fighters, who have seized large areas of Syria and Iraq in recent months. The United States has carried out air strikes on the group in Iraq and is considering its options in Syria.
In a picture posted online, a group of IS fighters in balaclavas are seen shooting at least seven kneeling men identified as Syrian army personnel. It was not possible to immediately confirm the authenticity of the images. Other photos showed groups of eight to 10 soldiers taken hostage, some with face wounds and three identified as officers.
The photos appeared to show at least two-dozen hostages. One picture reportedly shows the body of a pilot who had appeared on Syrian television before the attack on the base explaining how the army could easily defend it.
Others show militants holding up knives next to groups of captured men. Syrian state television aired a report last week interviewing army personnel at the base and showing its defenses, just before IS overran it. After the capture on Sunday, Syrian state television said the military was "regrouping" and that there was a "successful evacuation of the airport" as the army continued strikes IS areas close to the base.
The SOHR said 346 IS fighters were killed and more than 170 members of the security forces had died in five days of fighting over the base, one of the deadliest clashes between the two groups since the start of the war.
In a separate development, the U.S. said Tuesday it does not intend to coordinate with the Assad government on targeting the Islamic State on Syrian territory.
"There are no plans to coordinate with the Assad regime as we consider this terror threat," White House spokesman Josh Earnest said, after Syrian officials demanded Washington ask permission for any action over its territory.
Earnest spoke amid reports that U.S. spy planes and drones had already started flights over Syria to collect intelligence while President Obama contemplates air strikes.
Earnest dismissed Syrian demands that it be notified of any U.S. activity and offers to work with Washington to combat terrorism, saying that the U.S did not recognize the Assad government as the legitimate representative of the Syrian people.
Al Jazeera and wire services