At least 12 employees of the U.N.’s Palestinian refugee agency had connections to Hamas’s Oct. 7 attack on Israel and around 10% of all of its Gaza staff have ties to Islamist militant groups‚ according to intelligence reports reviewed by The Wall Street Journal. Six United Nations Relief and Works Agency workers were part of the wave of Palestinian militants who killed 1‚200 people in the deadliest assault on Jews since the Holocaust‚ according to the intelligence...