An 80mm mortar fragmentation round can travel almost 3.5 miles, and has a blast radius of over 70 ft. A proximity, or air burst, of such a round is a possible cause of the Gaza beach deaths. Arab militants trying to target Israeli artillery positions could have fired the errant round. Whatever, it's unreasonable, and senseless to point fingers during an artillery duel, and even more so to take family outings in their vacinity. Gazans must be immune to the sounds of war. Who could enjoy a beach picnic with artillery duels,and air raids going on around you? Why would you think you and your family would be safe anywhere in the area of such goings on? Who in the Negev villages is "Partying in the dunes" during such times?
Yemen's Houthi rebels commit to peace plan in letter to UN chief, BBC reports (Haaretz)
from the article: Peretz: Gaza beach blast may have internal Palestinian cause