Satellite images analyzed by The Washington Post show dozens of armored Israeli vehicles about 1½ miles north of Khan Younis — the biggest city in southern Gaza, which has become swollen with other Gazan refugees — about 9 a.m. Sunday local time. A ground incursion of Khan Younis would usher in a new stage of Israel’s war and may exacerbate the refugee crisis. “Almost 1.9 million people” in Gaza are internally displaced, equivalent to 80 percent of its population, according to U.N. figures released Monday. Aid groups and Palestinian families say Israeli maps directing them to “safer” areas are sowing confusion because they lack specifics, or those areas are overcrowded or under attack.