 Israeli tanks and military vehicles were seen moving in southern Israel on October 13 morning, ahead of an expected ground invasion into Gaza, after a devastating attack by the militant group Hamas.Israel's military on Friday called for all civilians of Gaza City, more than one million people, to relocate south within 24 hours. A movement of people the United Nations called impossible without devastating humanitarian consequences, Israeli warplanes continued pounding Gaza in retaliation for the weekend attacks by Hamas militants that killed more than 1,300 Israelis, mostly civilians.A ground invasion of the narrow and densely populated Gaza Strip, home to 2.3 million people and under siege by Israel, poses serious risk, with Hamas holding scores of hostages kidnapped in the assault.