The United Nations launched an appeal on Friday for $273.7 million to meet the humanitarian needs of Yemen over the next three months, as fighting intensifies in the south and air strikes pound 18 of Yemen's 22 provinces. A statement from the U.N. humanitarian agency OCHA cited local sources indicating 150,000 people had been displaced, 50 percent more than the previous U.N. estimate, and said health facilities had reported 767 deaths between March 19 and April 13, almost certainly an underestimate.