Israel bombed Palestinian militant targets in the Gaza Strip from air and sea for a fifth straight day on Sunday, preparing for a possible ground invasion while also spelling out its conditions for a truce.Palestinians launched dozens of rockets into Israel and targeted its commercial capital, Tel Aviv, for a fourth day. The "Iron Dome” missile shield shot down two of the rockets fired toward Israel’s biggest city but falling debris from the interception hit a car, which caught fire. Its driver was not hurt.In scenes recalling Israel’s 2008-2009 winter invasion of the Gaza Strip, tanks, artillery and infantry massed in field encampments along the sandy border. Military convoys moved on roads in the area newly closed to civilian traffic.Prime Minister Benjamin Netanyahu said Israel was ready to widen its offensive."We are exacting a heavy price from Hamas and the terrorist organizations and the Israel Defence Forces are prepared for a significant expansion of the operation,” Netanyahu said at a cabinet meeting, giving no further details.Palestinian officials said 56 Palestinians, most of them civilians, including 16 children, have been killed in small, densely populated Gaza since the Israeli offensive began, with hundreds wounded. More than 500 rockets fired from Gaza have hit Israel, killing three civilians and wounding dozens.Israel unleashed intensive air strikes on Wednesday, killing the military commander of the Islamist Hamas movement that governs Gaza and spurns peace with the Jewish state.Israel’s declared goal is to deplete Gaza arsenals and press Hamas into stopping cross-border rocket fire that has bedeviled Israeli border towns for years and is now displaying greater range, putting Tel Aviv and Jerusalem in the crosshairs.AIR STRIKE ON MEDIA CENTRESIn air raids on Sunday, two Gaza City media buildings were hit, witnesses said. Eight journalists were wounded and facilities belonging to Hamas’s Al-Aqsa TV as well as Britain’s Sky News were damaged.An employee of Beirut-based al Quds television station lost his leg in the attack, local medics said.The Israeli military said the strike targeted a rooftop "transmission antenna used by Hamas to carry out terror activity”, and that journalists in the building had effectively been used as human shields by the group.Three other attacks killed three children and wounded 14 other people, medical officials said, with heavy detonations regularly jolting the Mediterranean coastal enclave.Egyptian President Mohamed Mursi said in Cairo, as his security deputies sought to broker a truce with Hamas leaders, that "there are some indications that there is a possibility of a ceasefire soon, but we do not yet have firm guarantees”.