UNITED NATIONS (AP) — The U.N. humanitarian chief is warning that the world’s biggest humanitarian crisis in Yemen is getting even worse with the COVID-19 pandemic “roaring back” in recent weeks as the Arab world’s poorest country faces a large-scale famine. Mark Lowcock told the Security Counsel on Thursday that tens of thousands of people are already starving to death and another 5 million are just a step behind. Lowcock said that March was also the deadliest month this year for civilians, with more than 200 killed or injured as a result of hostilities — a quarter of them in the oil-rich central province of Marib.