In an none-too-surprising development in the story of the Afghan army beheadings, the "army" officer who made the original report has now retracted his statement in response to criticism from human rights groups. Apparently, beheading prisoners violates the Geneva Conventions.
I think the article's assertion that it was Human Rights Watch which claimed that the beheadings would be a war crime is wrong, as there is nothing in the News section of their website about it. Amnesty International has made a statement, however.