Syria conflict: Islamic State militants 'kill Syrian soldiers'
29 August 2014 Last updated at 01:29 BST
Dozens of Syrian army soldiers appear to have been killed by jihadist militants from Islamic State (IS), activists say.
The Syrian Observatory for Human Rights said the soldiers were captured while attempting to flee to Hama province after IS stormed the Tabqa airbase.
A video posted online purportedly shows the aftermath of the killings, with a long line of bodies of young men lying face down stripped to their underwear.
A second video, purportedly showing the beheading of a Kurdish man, has also been posted online.
The BBC's Middle East Regional Editor Sebastian Usher says the clips are "powerful, dark propaganda".