When the Israelites along the valley and those on the other side of the Jordan saw that the army of Israel had fled and that Saul and his sons had died, they abandoned their cities and ran away. So the Philistines came and occupied their cities.
Jewish Publication Society of America Version (JPS1917) - 1 Samuel 31:7 >And when the men of Israel that were on the other side of the valley, and they that were beyond the Jordan, saw that the men of Israel fled, and that Saul and his sons were dead, they forsook the cities, and fled; and the Philistines came and dwelt in them.