NEW : `` It is a complex situation with multiple armed groups , '' says UNAMID spokesman . All 25,000 inhabitants of the camp , which housed those displaced by conflict , have fled . The UN has been trying to get them back in for months Millions have been displaced and many killed in nine years of conflict in Darfur .
NEW : `` It is a complex situation with multiple armed groups , '' says UNAMID spokesman . All 25,000 inhabitants of the camp , which housed those displaced by conflict , have fled . The violence started 10 days ago with attacks on an official and the Kassab camp , U.N. says . Millions have been displaced and many killed in nine years of conflict in Darfur .