GENEVA: Thousands of children are facing an imminent risk of death as malnutrition rates skyrocket in the besieged city of al-Fashir in Sudan's Darfur region, four United Nations agencies said on Thursday. More than a quarter of a million civilians, about half of them children, have been cut off from food and healthcare in the city during a 16-month-old standoff, the agencies said. "Health facilities have collapsed, and thousands of children suffering from severe acute malnutrition are now without treatment," the agencies said.