Egypt warned Israel on Sunday against launching a massive military operation in Gaza, but Israeli defense officials said Cairo was angry with Hamas leaders for ending the six-month period of relative calm. "Egypt is very upset at Hamas, and understands that the leadership there needs to be replaced," one official told The Jerusalem Post. Officially, though, the Egyptians cautioned Israel against an escalation of violence. "We say such a move would have devastating consequences, devastating humanitarian consequences," Egyptian Foreign Ministry spokesman Hossam Zaki told the Post in a telephone interview. "This is something we cannot accept or condone under any terms." Meanwhile, defense officials revealed that Prime Minister Ehud Olmert and Defense Minister Ehud Barak met privately on Thursday and decided that Israel would respond militarily to rocket attacks against the western Negev. The timing of the operation will be determined at a later date, likely following a security cabinet meeting later this week. Hamas leaders went underground in Gaza on Thursday out of fear of being targeted by Israel as the movement announced that it would not extend its unofficial six-month cease-fire with Israel. Hamas also evacuated many of its institutions and security installations in anticipation of an escalation with the IDF, Palestinian sources said. The Post learned Sunday that the IDF Home Front Command had drawn up plans to evacuate children and elderly from Israeli towns that could come under heavy barrages of rockets in the event of a large-scale operation in Gaza. Defense officials said that Hamas was likely capable of firing more than 100 rockets a day into Israel throughout such an operation. On Sunday, Shin Bet (Israel Security Agency) chief Yuval Diskin told the cabinet that Hamas had rockets capable of reaching the outskirts of Beersheba. Nineteen rockets struck the Negev Sunday, in addition to at least three mortar shells. One person was lightly wounded and a rocket scored a direct hit on the home of Sderot resident Maya Iber, causing extensive damage. Another rocket struck near Ashkelon. Israeli aircraft fired missiles at a rocket launcher in northern Gaza. There were no reports of Palestinian casualties. "Nothing's changing, no one's doing anything - not the government, no one," Iber told Israel Radio. "Before 8 a.m. there was an alarm, a red alert. I was just about to go to work, and I turned back," she said. She added that she didn't have a safe room in her house, so when the alarm sounded she had taken shelter downstairs in the safest place she could find. She said that she heard the rocket struck, and "thought it had landed somewhere next to the house. I opened my eyes, and saw it had hit my house... I heard the explosion." Her children no longer lived in Sderot, said Iber, and she had been alone in the house. "The Kassams started falling in 2000, and one by one the children left Sderot." They had tried to convince her to leave too, she said. "I always tell them 'it'll be okay.' I love Sderot, and I have a nice house here." Though Kassams had struck close to her before, she said that now, after a Kassam actually hit her house, she would consider leaving. Zaki, the Egyptian spokesman, said that while Hamas used means that Cairo doesn't support or condone, "they are part and parcel of the Palestinian public." He said late Sunday that no progress had been made in trying to get the parties to renew the truce, and called Friday's expiration of the truce "a dangerous situation" that could escalate into confrontation. He added that Israel's closure policy, which he described as indiscriminate collective punishment, was "wrong and counterproductive." The policy "needs to be seriously reviewed and halted," he said. "We don't want anything from Hamas. They know what they are supposed to do: halt their rockets and that's it," Zaki said. Earlier this month, however, a top Egyptian parliamentarian from the ruling party warned that his country would not allow Hamas to establish an Islamist state in Gaza. Egypt has recently been subject to criticism because of Israel's strict closure on the Gaza Strip, he said. "It is giving us a lot of problems because it is causing the Palestinians, the civilians, severe hardship," he said. While some critics have suggested that Egypt open up the Rafah crossing between Gaza and Sinai to allow goods and persons to enter and exit freely, this was unacceptable to Egypt, Zaki said. "This would be very easy, for Israel to shut down its crossings and completely disconnect from the Gaza Strip and ask Egypt to take over," he said. In a press statement put on the Foreign Ministry's Web site on Sunday, Zaki said Israel's unilateral disengagement from Gaza in 2005 had not resulted in the Strip's liberation from occupation as some believe or claim. "Evidence of Israel's occupation is that it is still in control of Gaza's airspace, seas, most of the Strip's borders and most ports of entry and exit of goods and individuals," he said in the statement. The West Bank, the Gaza Strip and east Jerusalem formed a single geographic unit and should not be dealt with on a piecemeal basis, the statement said. Meanwhile, the Egyptian Red Crescent Society said it would send five trucks carrying food and medical aid to the Gaza Strip on Monday, according to Reuters. An Egyptian official told the wire service that Egyptian authorities had agreed with Israel to allow the trucks into the coastal strip. Jerusalem Post staff contributed to this report.