Pakistan's army chief has ordered an inquiry into a video that showed the killing of six unarmed men allegedly by an army firing squad. The video, which was apparently shot with a mobile phone, appeared on a website several weeks ago. It showed a group of men in army uniform drag six blindfolded civilians into a line and then shoot them. Last year the Pakistani army conducted a major operation against Taliban militants in the north-western district of Swat where it was often accused of carrying out extrajudicial killings of suspected militants.