In this photo taken Monday Aug. 29, 2016, a woman with her malnourished children sit at a feeding centre run by Doctors Without Borders in Maiduguri, Nigeria. The whimpers from skeletally thin babies too weak to cry out are a harbinger of worse things to come: A quarter of the kids lucky enough to make it to this emergency feeding center are dying _ the latest victims of Boko Haram's Islamic insurgency.
Close to 20 million people in three African countries and Yemen are at risk of starvation. The UN secretary general says more than $4bn is needed within the next three weeks or many more will die. Antonio Guterres made an emergency visit to Somalia, where a national disaster has been declared because of drought. About half of the country's population faces severe food shortages. In South Sudan, famine has been declared in parts of the country.