DEIR AL-BALAH, Gaza Strip — Israeli airstrikes killed at least 31 people in the Gaza Strip in the past 24 hours, including 11 at a makeshift cafeteria in an Israeli-declared humanitarian zone, medics said. In Lebanon, warplanes struck Beirut’s southern suburbs and killed six people east of the city on Tuesday. The new bombardment on both fronts comes on the verge of a deadline set by the United States for Israel to dramatically ramp up humanitarian aid allowed in Gaza or risk possible