The controversial US assassination drone attacks have come under fire again. A UN investigation has so far identified 33 drone strikes around the world that have resulted in civilian casualties and may have violated international humanitarian law. The 22-page document, published by the UN’s special rapporteur on human rights, Ben Emmerson, examines incidents in Afghanistan, Yemen, Iraq, Libya, Somalia, Pakistan and Gaza. Emmerson says he’s been told that in Pakistan alone at least 400 civilians had been killed in the US strikes since 2004. Some estimates put the toll at a much larger number but the US has been mum about the death toll. It is not even clear how the US classifies who is a civilian and who is not. The UN report urges Washington to make public its data about drone strikes and civilian casualties.