Omar Saleh was leading a peaceful and comfortable life as a trauma surgeon and university lecturer in Egypt when the call came from the United Nations health agency: surgeons urgently needed in war-torn Somalia. He didn't have to think twice.

"I should be where I'm needed," he said today as the UN prepared to mark World Humanitarian Day on Friday. "And this is where I'm needed. I'm a trauma surgeon. This is a conflict. Trauma is everywhere. I must be there," he told the UN News Centre by telephone by telephone.