CAIRO (AP) — Drone warfare has become the deadliest threat to civilians in Sudan ‘s conflict and both the military and the rival paramilitary Rapid Support Forces are being supplied by a number of countries in the Middle East and beyond, experts say. “Armed drones have now become by far and away the leading cause of civilian deaths,” or over 80% of conflict-related deaths, United Nations human rights chief Volker Türk said this week, calling for measures to prevent their transfer to Sudan.