In this photo released by the United Nations Mission in Sudan (UNMIS), U.N. Security Council delegation members Susan Rice (center), U.S. ambassador to the United Nations, and Nestor Osorio (leaving helicopter) of Columbia arrive in Malau, Sudan, on Tuesday, May 24, 2011. Seventy northern Sudanese troops were killed and more than 120 are missing from an attack last week by southern Sudanese forces near the disputed region of Abyei, a Sudanese diplomat said Tuesday, while Ms. Rice called the incident a "serious violation" of the peace agreement. (AP Photo/UNMIS, Paul Banks)
