RAFAH, Gaza Strip — Israeli strikes on the southern Gaza city of Rafah overnight killed 22 people, including 18 children, health officials said Sunday, as the United States was on track to approve billions of dollars of additional military aid to Israel, its close ally. Israel has carried out near-daily air raids on Rafah, where more than half of Gaza’s population of 2.3 million has sought refuge from fighting elsewhere. It has also vowed to expand its ground offensive to the city on the border