A video apparently released by the Islamic State group shows 25 men being shot dead in the ancient city of Palmyra, in Syria.
IS said the men were soldiers captured in the city of Homs. They were shot dead inside Palmyra's amphitheatre.
Stills from the video showed the killers to be young males, possibly even as young as 13 or 14.
IS captured the site and the neighbouring city of Palmyra in late May.