BEIRUT — New images of mass killings, including some showing masked militants shooting kneeling men after the capture of a strategic air base in Syria, emerged Wednesday on the website of the Islamic State of Iraq and Syria.
In one photo, masked gunmen were seen shooting seven men kneeling on the ground, some dressed in what appeared to be Syrian military uniforms, after the seizure of the Tabqa air base in the province of Raqqa earlier this week.
The photos underscored how the group uses violence and images of violence to terrorize its opponents, as it sweeps further into Syria and Iraq, where it has imposed an Islamic state, or caliphate, governed by its harsh interpretation of Islamic law.
Some photos showed captured Syrian soldiers, many with bloodied and swollen faces. In one, a masked ISIS fighter stood behind a group of soldiers brandishing a knife of the type the militants have used in the past to behead victims, including American journalist James Foley. In another, a militant grinned as he pressed a double-edged sword against the neck of a captured soldier inside a jeep.
One photograph showed a headless corpse, while another showed 10 slain men, sprawled in a pool of blood on a dirt road. It wasn't clear whether they were killed during the clashes or after being captured.
Videos uploaded to social media networks also showed the aftermath of the battle, including footage of the charred bodies of Syrian soldiers. One video showed about 200 captured soldiers being marched through the desert in their underwear to an unknown fate as militants made the sounds of shepherds herding goats or sheep.
The 36 photos and video images corresponded to reporting by the Associated Press of ISIS militants' seizure Sunday of the air base, which had been the last government-held outpost in Raqqa, a province now dominated by the jihadi group. Militants also captured the bases' weaponry, including artillery and mounted machine guns.
The images emerged as a United Nations commission accused the group of committing crimes against humanity in Syria. The United Nations had earlier accused the group of similar crimes in Iraq.
"This is a continuation — and a geographic expansion — of the widespread and systematic attack on the civilian population" by ISIS, said the four-member commission, chaired by Brazilian diplomat Paulo Sergio Pinheiro.
Pinheiro told reporters that one of the most disturbing findings was the existence of large training camps where boys, some as young as 14, are recruited and trained to fight alongside adults.