The United Nations is warning up to a quarter of the population of Central African Republic is at risk of going hungry amid a violent sectarian crisis. Fighting between Muslims and Christians has killed more than 500 people in the capital Bangui. The Muslim president has signaled he may be open to negotiations with Christian militias. But the head of the U.N. World Food Program warned the violence could leave a lasting impact.

Ertharin Cousin: “We’ve identified that there are probably 1.3 million people who are food insecure. And we also know that because the farmers haven’t been able to access their farms, that we’ve missed this year’s planting season, so that when we get to the harvest in the spring, the problem will be even more exacerbated.”

Last week, the aid group Doctors Without Borders criticized what it called an “appalling performance” by U.N. agencies in Central African Republic, saying there had been “no evidence of an adequate humanitarian reaction” there.