Representatives from Ethiopia’s government and rebel forces in Tigray gathered in South Africa Monday for peace talks mediated by the African Union. The talks came as the United Nations warned the situation in Ethiopia is spiraling out of control, with reports of widespread atrocities including airstrikes and artillery fire that have exacerbated a humanitarian catastrophe. Some estimates put the number of dead in Tigray at 800,000 since fighting erupted less than two years ago. The U.N. says the resulting health crisis now threatens 6 million people.