When boys and girls started arriving at his hospital with missing arms and feet, they were the first casualties of war Dr Tom Catena had seen.
"The injuries are horrifying," said the mission doctor who comes from upstate New York, "a girl with her feet blown off, another with her abdomen sliced open."
The victims pouring in from the villages in Sudan's Nuba mountains were being bombed by their own government, he discovered. Grass thatch villages were being turned to charnel houses as an air force dropped bombs from the back of ageing cargo planes. The government in Khartoum insists it is targeting armed rebels but the Antonovs it is using are non-military aircraft and are randomly destructive.
"The worst injuries are from the Antonovs," said Dr Catena. "This is my first experience of war and you don't understand the human toll until you see it. "These people are being destroyed for nothing." The only qualified doctor in an area with hundreds of thousands people, the mission hospital has about 400 patients.
The doctor who arrived recently from mission work in Kenya said he was nervous at first about speaking out as hospitals were targets. "Why hold back?" he asked. "We should show what's happening, this is the reality."
Yussef Abdullahi Kuwa reached the hospital in the north of the Kauda Valley on Sunday. The 15-year-old was playing iwhen the bomb hit. He was unable to take cover fast enough and now half his face is missing where hot metal sliced through it. He cannot speak.
"My boy has done nothing to this government," said his father, who took three days to get him to a doctor. "We are powerless." Children with stumps where their hands or feet should be wander around in the hospital. Sixteen-year-old Jakumo lost his left arm after helping his sister with the washing. The children had been told to lie flat when they heard planes but Jakumo forgot. "I tried to hide behind a tree instead," he said. "But it hit me."
The UN Security Council announced yesterday that all its peacekeepers were being withdrawn from Sudan's southern border areas by the end of next month. Sudan's President Omar al-Bashir, who is wanted at The Hague for war crimes, also threatened to expel aid agencies in Southern Kordofan state where the fighting is taking place.