Sporadic missile fire from the Gaza Strip hit southern Israel on Monday for a fourth straight day, with Egypt trying to secure a truce and Israel warning it would toughen its response if the violence continued. A Palestinian official with knowledge of Egypt’s diplomatic efforts said that although there was no formal truce in place, Hamas understood the need for calm. The official said another group, Islamic Jihad, also acknowledged the ceasefire. “The Islamic Jihad did not fire since last night. This means they have accepted the understanding too,” the official said. Monday’s launches were claimed by smaller groups, such as the radical Salafi organisation, the Shoura Council of the Mujahedeen, and Israeli leaders are likely to come under strong domestic pressure to respond with force if the hits continue. The Israeli military said Palestinians had fired 11 rockets through the morning, ending an overnight lull and adding to more than 110 launched in the preceding 72 hours. “We have a full box of tools ... that we have not yet used,” Israeli Vice Prime Minister Moshe Yaalon told Army Radio. “We will need to toughen our response until Hamas says ‘enough’ and ends the fire.” The European Union voiced concern on Monday about the latest flare-up of deadly violence on the Israeli-Gaza border and called on both sides to show restraint. Six Palestinians were killed in a round of tit-for-tat attacks that kicked off on Saturday including a barrage of rocket fire from Gaza that wounded eight people in Israel. “I am very concerned by the latest escalation of violence between Gaza and Israel,” European Union foreign policy chief Catherine Ashton said, condemning the firing of rockets and mortars into Israel. “I... call on both sides to refrain from exacerbating the situation,” she said in a statement, adding that she supported efforts by Egypt to try to broker a truce. “There is no place for violence in the Middle East. It is only through resumed negotiations that the legitimate aspirations of both Palestinians and Israelis will be met, through a two-state solution.” Meanwhile, a spokesman for the Palestinian president says the Palestinians will proceed with asking the UN General Assembly to recognise a Palestinian state, despite a personal call from President Barack Obama to abandon the bid. Nabil Abu Rdeneh said President Mahmoud Abbas had a long phone conversation with Obama on Sunday evening. He said Obama “expresses his opposition to this step,” but Abbas replied he would carry on. In Washington, the White House press office said that Obama “reiterated the United States’ opposition to unilateral efforts at the United Nations.” Obama also “reaffirmed his commitment to Middle East peace and his strong support for direct negotiations between Israel and the Palestinians” for a peace accord, the White House said. Abbas met Saudi King Abdullah Bin Abdul Aziz Al Saud on Monday, SPA state news agency said. The two leaders discussed “developments in the Palestinian issue, as well as the obstacles facing peace in the region and the situation in the occupied Palestinian territories,” the agency in a brief report. Israel claimed on Monday that 11 rockets were fired from insiade Gaza into southern Israel, one of which exploded next to a house, shattering an overnight calm even as Cairo sought to broker an end to 24 hours of bloodshed.