GAZA CITY, Gaza Strip (AP) — Hamas and Israel blamed each other for an explosion at a Gaza park Monday that killed at least 10 Palestinians — including nine children playing on a swing — in a horrific scene that underscored the heavy price civilians are paying in the conflict. The streets near the park were strewn with shattered glass from homes and shops, and the ground was marked with the bloody footprints of those who helped carry the bodies to ambulances. The United Nations on Monday called for an immediate cease-fire in the fighting that has killed at least 1,085 Palestinians, 52 Israeli soldiers and three civilians on the Israeli side. In another tragic episode involving children, four Palestinian boys, cousins ages 9 to 11, were killed July 16 on a beach west of Gaza City by shellfire from a navy ship. Israel blames the civilian deaths on Hamas, accusing it of firing from residential neighborhoods and using civilians as human shields. The Israeli military says it is doing its utmost to spare civilians, including issuing evacuation warnings to homes and neighborhoods that are about to be hit in Israel's air and ground operation.