An upsurge of violence across southern Sudan is creating a “health catastrophe,” say experts in the field. As the World Health Organization mobilises urgent additional resources to cope with the crisis, the World Food Programme, warning that the region faces a “massive food deficit,” has started emergency air drops of supplies.

More than 1200 people have been killed in a series of armed attacks and ethnic clashes in the region this year—more than the current death toll in Darfur, in the west of the country—leading to mounting concerns that this could presage a return to all-out war. WHO’s secretary general, Ban Ki-moon, said he was “deeply concerned over the string of attacks and counterattacks” and the killing and displacement of “innocent civilians.”

A WHO spokesman said last …