Islamic State (ISIS) fighters executed scores of Syrian soldiers captured when the militants seized an airbase in the province of Raqqa at the weekend, according to a video posted on YouTube Thursday.
The video, confirmed as genuine by an Islamic State fighter, showed the bodies of dozens of men lying face down wearing nothing but their underwear. They were stretched out in a line that appeared to be dozens of metres long.
A separate pile of bodies was shown nearby. Reuters could not independently verify the authenticity of the video.
The caption beneath it said the dead numbered 250. An ISIS fighter in Raqqa told Reuters via the Internet: “Yes, we have executed them all.”
The Syrian Observatory for Human Rights, which monitors violence in the war, put the death toll at more than 120.
ISIS, a radical offshoot of al Qaeda, stormed Tabqa airbase on Sunday after days of clashes with the army and said it had captured and killed soldiers and officers in one of the bloodiest confrontations yet between the two sides.
The capture of Tabqa has cemented its grip on the north of the country.