A UN investigator has called on Washington to provide justification for the increasingly widespread use of military drones to carry out targeted killings. He says drone attacks, which take innocent civilian lives, may be violating international law.

The US military and CIA use drones in Afghanistan, Pakistan, Iraq, Yemen and Somalia. Washington should clarify the legal basis for the policy of killing suspected Al Qaeda and Taliban leaders and associates rather than trying to capture them, Christof Heyns, Special Rapporteur on Extrajudicial, Summary or Arbitrary Executions, said in a report. The 28-page document addressed to the UN Human Rights Council was released ahead of the body’s debate on the issue in Geneva.