Palestinians searched for survivors in Gaza Sunday, after an Israeli air strike destroyed several homes and killed dozens, including at least 10 children - according to health officials - as Hamas militants fired rockets at Israel with no end in sight to seven days of fighting.The Israeli military said in a statement that the civilian casualties were unintentional, saying its jets attacked a tunnel system used by Hamas, which collapsed, bringing the homes down.Hamas, the militant group that controls Gaza, called it a "pre-meditated killing." On CBS's "Face the Nation" Sunday, Israeli Prime Minister Benjamin Netanyahu echoed his military’s assertion that Israel tried to avoid civilian casualties, but that Hamas bore responsibility for "intentionally locating its military infrastructure under civilian houses."NETANYAHU: "We are targeting a terrorist organization that is targeting our civilians and hiding behind their civilians, using them as human shields. We're doing everything we can to hit the terrorists themselves..."Netanyahu also defended an Israeli air strike on Saturday that destroyed a 12-story building where the Associated Press and the Al Jazeera TV network had offices, saying Israel had informed the U.S. of the attack.NETANYAHU: "We share with our American friends all that intelligence, and here's the intelligence we had: it's about Palestinian terrorist, uh, an intelligence office for the Palestinian terrorist organization housed in that building that plots and organizes terror attacks against Israeli civilians, so it's a perfectly legitimate target."The Associated Press has condemned the strike and asked Israel to put forward its evidence that Hamas was in the building. ANTONIO GUTERRES: "The current hostilities are utterly appalling."Meanwhile, in New York, U.N. Secretary-General Antonio Guterres called for an immediate end to fighting at the Security Council's first public meeting on the conflict.GUTERRES: "Fighting must stop."Hamas began its rocket assault last Monday after weeks of tensions over a court case to evict several Palestinian families in East Jerusalem, and in retaliation for Israeli police clashes with Palestinians near the city's Al-Aqsa Mosque during the Muslim holy month of Ramadan. On Sunday, video obtained by Reuters showed a car ramming into an Israeli police roadblock in East Jerusalem, where authorities said six police officers were injured in the incident, and that the driver of the vehicle was shot dead at the scene.Later, in a statement, a spokesman from Hamas praised what he called a "heroic and daring operation."