JERUSALEM (Agencies) - Israel on Wednesday rejected world calls for a truce and pressed on with its deadly Gaza offensive, as warplanes pounded Hamas targets for a fifth day and the Islamists shot back with rockets. "The cabinet decided to continue with the military operation," a senior government official told AFP after a six-hour meeting of the country's security cabinet that debated international truce proposals. Israeli Prime Minister Ehud Olmert told the meeting that conditions were not yet ripe to halt the bombardment launched in response to persistent rocket fire from the enclave that Hamas has run for a year and a half. "We did not launch the Gaza operation only to end it with the same rocket firing that we had at its start," the official quoted Olmert as saying. "If the conditions are ripe and we think that they might offer a solution that will guarantee a better security reality in the south, then we would weigh the issue. We are not there yet." Amid mushrooming protests around the globe, world diplomats have been scrambling to find a way to stop one of Israel's deadliest ever offensives on the Gaza Strip that has so far killed at least 393 Palestinians. There was no let-up in the Israeli attacks on Wednesday, with Israel conducting nearly 60 airstrikes and Hamas firing more than 50 rockets. The Islamist movement vowed on Wednesday to fight "until the last breath" if Israel makes good on its threat to send ground forces into its Gaza stronghold, which it has bombarded for five days. "We in Hamas are ready for all scenarios and we will fight until the last breath," senior official Mushir al-Masri told AFP. "Israel will embark on a veritable adventure if it decides to invade Gaza. We have prepared surprises for them," he vowed. The movement Another senior Hamas official Ayman Taha told AFP that the movement had not received any truce proposals but was ready to consider any that are made that would end the Israeli offensive on its Gaza stronghold and its blockade of the enclave. "No truce initiative has been sent to us," said Taha. "If such a proposition is made to us, we will examine it as we are favourable to any initiative that will put an end to the aggression and totally lift the blockade," senior Hamas official Ayman Taha said in Gaza. The exiled head of Hamas, Khaled Meshaal, echoed the sentiment in a phone call with Russian Foreign Minister Sergei Lavrov, voicing "readiness to cease armed confrontation but on condition of the lifting of the blockade of Gaza," the Russian ministry said in a statement. Earlier, a Hamas spokesman blasted as unbalanced the terms of international ceasefire proposals in Gaza. "The current efforts aimed at ending the combat and installing a ceasefire put the executioner and the victim on equal footing," Fawzi Barhum said in a statement. "Our ground forces are still deployed around the Gaza Strip and are ready to go in, if given the order," an Israeli army spokeswoman told AFP on Wednesday. Since it was launched on Saturday, the Israeli offensive has killed at least 393 people, including 42 children, and wounded more than 1,900 others, according to Gaza medics. At least 25pc of those killed have been civilians, the United Nations said. The intensive bombardment has reduced much of Hamas' administrative infrastructure in the territory to rubble but has failed to stop rocket fire into Israel. Since the start of the Israeli onslaught, Hamas activists have fired more than 250 rockets, killing three civilians and one soldier and wounding several dozen people. Israel opened one of its border crossings with Gaza again on Wednesday, bringing to 179 the number of lorryloads of supplies delivered since the Gaza bombardment began, the army said.