MOGADISHU Somalia (Xinhua) -- Walter Kaelin, a UN Special Advisor on Internal Displacement, said some 2.6 million Somalis are internally displaced, noting that that is quite a large number in terms of the overall population. ?This is a huge humanitarian challenge but it?s also affecting the development of the country and ultimately the security, the state-building,? Kaelin said in a statement issued by the United Nations Assistance Mission in Somalia (UNSOM). The return of refugees across neighboring countries and internal displacement have been key...