Channel 4 News reveals images of the men caught on camera apparently taking part in executions in Sri Lanka, actions a top lawyer has branded "war crimes". Can you help identify the men involved?
Warning: There are disturbing images in the videos on this page.
The UN has told Channel 4 News that the Sri Lanka apparent execution video, broadcast on Tuesday, deserves further investigation.
The UN Special Rapporteur on extrajudicial, summary or arbitrary executions, Professor Christof Heyns, said: "It is shocking indeed, and clearly deserves more investigation," he said.
Mark Ellis, Executive Director of the International Bar Association (IBA), told Channel 4 News the video was prima facie evidence of war crimes being committed.
"This is a very disturbing video and clearly, on the face of it, shows war crimes have been committed and perhaps crimes against humanity, depending on who the group targeted was.
"There is no question that this video is prima facie evidence that these crimes were committed. And therefore there's a responsibility on the part of the international community to push for an investigation and prosecution."
The video appears to show government troops executing civilians in the last few weeks of the 26-year Sri Lanka war, which ended last year when Sri Lanka declared victory over the Tamil Tigers.
