Israeli tanks massed at the Gaza border today as warplanes again pounded Hamas targets in the densely populated enclave where raids have killed more than 280 people in less than 48 hours. Dozens of tanks and personnel carriers idled at several points near the border after Israel warned it could launch a ground offensive in addition to its massive air bombardment. Hamas responded by firing rockets the farthest yet into Israel, with one striking not far from Ashdod, Israel's second-largest port, some 30km north of Gaza. It caused no casualties, medics said. The Israeli defence minster Ehud Barak vowed to "expand and deepen" the bombing blitz, unleashed in retaliation for persistent rocket fire by militant groups. "If it's necessary to deploy ground forces to defend our citizens, we will do so," his spokesman quoted him as saying. The cabinet gave the green light to call up 6,500 reserve soldiers, a senior official told reporters after the meeting. Warplanes continued to pound the territory of 1.5 million people, where many streets were deserted and schools and shops stayed shut as hundreds of funerals were held. Jets bombed a series of tunnels on Gaza's border with Egypt - a lifeline for Hamas used for smuggling in goods and weapons into the enclave. Businesses in the occupied West Bank, including annexed Arab east Jerusalem, observed a strike in protest at the onslaught, which has killed at least 282 people and wounded more than 600 since early on Saturday, according to medics. The Israeli prime minister Ehud Olmert said the campaign was launched "in order to regain a normal life for the citizens in the south who have suffered for many years from incessant rocket, mortar and terror attacks." Israel is "aiming to change the situation on the ground whereby in the future there will be a tranquil border between Israel and Gaza," the welfare minister Isaac Herzog said. But Hamas, which has controlled Gaza since ousting forces loyal to the Western-backed Palestinian president Mahmud Abbas in June last year, remained defiant. Its exiled leader Khaled Meshaal called in Damascus for a new Palestinian intifada, or uprising, against Israel and promised more suicide attacks. Hamas's last suicide bombing in Israel was in January 2005. The Israeli bombardment, one of the bloodiest 24-hour periods in its 60-year conflict with the Palestinians, sparked huge international concern. In New York, the UN Security Council called for an "immediate halt to all violence" and urged all sides "to stop immediately all military activities." Egypt, which had brokered a six-month truce between Israel and Hamas that expired on Dec 19, said it was trying to negotiate a new ceasefire. In the latest plea for the violence to end, Pope Benedict XVI implored the international community to do "all it can to help the Israelis and Palestinians on this dead-end road... and not to give in to the perverse logic of confrontation and violence." But a senior Israeli official said "we have our goals and our timetable and we don't seek mediation." Israel's main ally Washington has blamed Hamas "thugs" for provoking the offensive by firing rockets into the Jewish state from Gaza, and urged Israel to avoid causing civilian casualties. Amid the bombing, Mr Barak authorised the passage of an aid convoy into Gaza today, his spokeswoman said. Israel has kept Gaza largely sealed off since the Hamas takeover allowing only very limited supplies of basic goods into the aid-dependent territory. Egypt, which has slammed Israel over the bombing campaign, today criticised Hamas for not allowing hundreds of wounded to enter its territory through the Rafah border crossing - Gaza's only one that bypasses Israel - to receive medical treatment. Israel unleashed "Operation Cast Lead" against Hamas in the middle of Saturday morning, with some 60 warplanes hitting more than 50 targets in just a few minutes. By today, some 230 targets had been hit, the military said. Hamas has responded by firing more than 90 rockets and mortar rounds at Israel, killing one man and wounding a handful of other people. Army chief Lieutenant General Gabi Ashkenazi told the cabinet today that half of Hamas's rocket launch sites were destroyed in the initial wave of Israeli attacks. "Hamas was dealt a surprising and hard blow yesterday," a senior official quoted him as saying. *AFP