Entire mosques were leveled, appearing from the air as piles of rubble. Israel hit more than 1,000 targets in Gaza, its military said, including airstrikes that leveled much of the town of Beit Hanoun in the enclave’s northeast corner. More than two days after Hamas launched its unprecedented incursion from Gaza, the military said the fighting had largely died down for now. The attack caught Israel’s vaunted military and intelligence apparatus completely off guard, bringing heavy battles to its streets for the first time in decades. Israel formally declared war on Sunday, portending greater fighting ahead, and a possible ground assault into Gaza — a move that in the past has brought intensified casualties. Palestinian militants continued firing barrages of rockets, setting off air raid sirens in Jerusalem and Tel Aviv. Civilians are already paying a high price. Around 700 people have been killed in Israel — a staggering toll by the scale of its recent conflicts. Nearly 500 have been killed in Gaza, a tiny, impoverished enclave of 2.3 million Palestinians bordering Israel and Egypt. Palestinian militant groups claimed to be holding over 130 captives from the Israeli side. Hamas has been branded a terrorist organization by the West and Israel. Hamas refuses to recognize the state of Israel and opposes the interim Oslo peace accords which Israel and the Palestinian Liberation Organization negotiated in the mid-1990s. Hamas won Palestinian parliament elections in 2006, and seized full control of Gaza in 2007, after driving out the forces loyal to its political rival, internationally recognized Palestinian President Mahmoud Abbas.