The U.N. Office of the High Commissioner for Human Rights has announced a new investigation of the civilian toll of U.S. drone strikes overseas. Ben Emmerson, the U.N. special rapporteur on human rights and counter-terrorism, unveiled his inquiry on Thursday.

Ben Emmerson: “The central objective of the investigation I’m formally launching this morning is to look at the evidence that drone strikes and other forms of remote targeted killing have caused disproportionate civilian casualties, in some instances, and to make recommendations concerning the duty of states to conduct thorough, independent and impartial investigations into such allegations.”

The U.N. probe comes as the Obama administration appears to be escalating its drone warfare abroad, launching more than a dozen attacks in Yemen and Pakistan already this year. This week, the United States launched at least five drone strikes in Yemen in as many days. According to some reports, the latest attack mistakenly killed two Yemeni children.