"The goal of the operation is to send Gaza back to the Middle Ages," Israeli Interior Minister Eli Yishai, a member of the ultra-orthodox Shas party, said , according to the leading Israeli daily Haaretz. "Only then will Israel be calm for 40 years."The Orthodox Jewish news site Yeshiva World News also quoted Yishai as saying, "We must blow Gaza back to the Middle Ages, destroying all the infrastructure including roads and water."There was no calm in Gaza as 'Operation Pillar of Defense,' Israel's air and sea bombardment of the densely populated enclave, entered its fifth straight day on Sunday. Israel has carried out 950 air strikes targeting Palestinian militants who have launched more than 500 rockets into Israel during the course of hostilities.Reuters reports that the Palestinian death toll stood at 47 going into Sunday morning. Around half of those deaths were civilians, including 12 children. Gaza health officials said that 385 Palestinians have been wounded. The World Health Organization warned that Gaza's hospitals are overwhelmed with casualties from Israel's five-day bombing campaign.Three Israeli civilians have been killed by Gaza-launched rockets. Another 63 Israelis have been wounded, the New York Times reports Hostilities and tensions escalated on Saturday as Israeli forces bombed Hamas government buildings as well as the homes of Hamas Prime Minister Ismail Haniyeh and a leading Hamas military commander.Israel also bombed two media centers . One building housing Hamas-run al-Quds TV was hit, wounding three employees. Al-Quds cameraman Khader al-Zahar had one of his legs blown off.A pair of pre-dawn Israeli attacks on the Jebalya refugee camp also killed a child and wounded at least 12 other people.Hamas remained defiant in the face of the overwhelming Israeli onslaught, vowing that this is "only the beginning" and claiming that the militant resistance group "is still strong enough to destroy the enemy."Meanwhile, Israel's cabinet approved the mobilization of as many as 75,000 reserve troops for a possible ground invasion of Gaza. Thousands of these, along with tanks, artillery and other vehicles and equipment, are massing near the Gaza border.Egyptian President Mohamed Morsi , who called Israel's actions "blatant aggression against humanity," led efforts to broker a truce. Morsi said that "there are some indications that there is a possibility of a cease-fire soon, but we do not yet have firm guarantees."Israeli officials had no comment about any possible negotiations.Israel's defenders, including US President Barack Obama, claim that the Jewish state has a right to defend itself against the thousands of rockets that have been launched against it from Hamas and other militant groups.Some critics say those militant groups are resisting decades of Israeli occupation and oppression. Leading international figures, including Nobel Peace laureates Nelson Mandela Mairead Maguire and Jimmy Carter , accuse Israel of apartheid. United Nations human rights official Richard Falk and others, including Holocaust survivors , go even further, accusing Israel of ethnic cleansing in Palestine.British Prime Minister David Cameron has called Gaza a "prison camp" and a recently-released United Nations report says the besieged enclave will be uninhabitable by the year 2020, barring "urgent action."