Israel’s military is expanding its ground operation against Hamas across the Gaza Strip, a spokesman said. As the hostilities resume, many civilians already displaced by the conflict are again being forced to flee as the fight moves south. An estimated 1.8 million people — or 80 percent of the population of Gaza — are now internally displaced, according to the U.N. Office for the Coordination of Humanitarian Affairs. Aid groups and Palestinian families say maps posted online by Israel directing them to “safer” areas are sowing confusion because they lack specifics or those areas are overcrowded or under attack. The death toll continues to rise, with at least 316 people killed in the past day, the Gaza Health Ministry said Sunday, adding that more are likely buried under the rubble.