Their visit came as the United Nations human rights group warned that Sudan’s expulsion of 13 aid organizations from Darfur could also constitute a war crime. Sudan took the step in retaliation after the Netherlands-based International Criminal Court issued a warrant against President Omar al-Bashir on Wednesday.. The expulsion raised fears of a humanitarian crisis…Some 2.7 million people have been forced from their homes, and many rely on aid groups for food, water, shelter and medical care.