The IDF closed down Highway 10 along the Israeli-Egyptian border from Gaza to Eilat Thursday night in a concrete sign of heightened Israeli concern that the breached border between Gaza and Egypt will lead to increased terrorism against Israel. Defense officials expressed concern that terrorists were among the hundreds of thousands of Gazans to swarm into Egypt over the last 48-hours and would try to launch attacks from Sinai along the long border into Israel. The IDF is also in contact with communities in the western Negev to provide them with security updates and assessments. The chaotic situation in Gaza sent the IDF and the Israel Police on high alert along the Israeli-Egyptian border. Last year, three Israelis were killed in a suicide bombing in Eilat carried out by a Palestinian from Gaza who crossed into the Sinai Desert and from there into Israel. In addition, the National Security Council's counter-terrorism bureau issued a warning Thursday recommending that Israelis avoid visiting Sinai and that any Israelis currently there "leave forthwith." "Warnings of terrorist attacks in Sinai have recently intensified," a statement issued by the bureau read. "Terrorists in Sinai are working to abduct Israelis in Sinai and convey them to the Gaza Strip. The currently open border between the Gaza Strip and Sinai makes it easier for terrorists to move back and forth." Diplomatic officials said Israel was carefully monitoring the situation, but had not yet come to any policy decisions as to how to react. One official said the government was split between those who thought that the recent events provided Israel with a perfect opportunity to completely disengage from Gaza, and let the Egyptians deal with Gaza's humanitarian needs, and those who fear that an open border with Egypt will quickly transform Gaza into southern Lebanon before the 2006 war in terms of the quantity and quality of arms. The official said that Egypt was taken by surprise by the incident, and that any public pressure by Israel on Egypt at this time to retake control of the border would not be particularly effective. While no special governmental forum was convened Thursday to deal with the situation, sources in the Prime Minister's Office said that Prime Minister Ehud Olmert held consultations on the matter with various security officials throughout the day. Visiting US Under Secretary of State for Political Affairs Nicholas Burns said the US was following the events with a "great deal of concern." He said the US has been in touch with the Egyptians over the last 24-hours and "obviously want to be supportive of the Egyptian government's effort to regain a measure of control over that border." He would not elaborate. Burns, in the country for 48 hours for a high-level strategic dialogue with Israel, said he had not heard during his talks here of any Israeli plan to use the opportunity to "disconnect totally" from Gaza. Nevertheless, defense officials said they believed a "unique opportunity" had evolved out of Cairo's opening of the Gaza border that enables Israel to relinquish responsibility over Gaza to Egypt. Officials said it would be up to the government to institute such a policy. "We are prepared to shut down all of the crossings and once and for all complete the disengagement from the Gaza Strip," a senior defense official said. "For this to happen we would need a direct order from the political echelon." Deputy Defense Minister Matan Vilna'i expressed this thinking on Thursday, saying "we need to understand that when Gaza is open to the other side, we lose responsibility for it." "We want to stop supplying electricity to them, stop supplying them with water and medicine, so that it would come from another place," he said. It was not clear whether Vilna'i was expressing the view of the government, or was testing international receptiveness to such idea. Defense Minister Ehud Barak, speaking on the sidelines of the Davos Economic Forum in Switzerland, refrained from backing up his deputy. "I don't want to go too far in my interpretation of this," Barak said. Defense officials expressed concern with the current situation along the Egypt-Gaza border and warned that as long as a new fence was not erected, Hamas would be able to speed up its armament. "They no longer need tunnels," one official said. "Now instead of smuggling explosives and weaponry into Gaza underground, they can do it above ground." Meanwhile, Palestinian Authority President Mahmoud Abbas related to the situation after a meeting in Ramallah with a group of Kadima MKs. "The closure of the crossings in Gaza is a mistake," he said. "It is wrong to starve the residents and prevent them from receiving food and electricity." Burns also addressed the hardships being faced by the Gazan residents, saying that the US "thinks it is important that the residents of Gaza who are victims of this, have their basic needs restored, and I hope that is done relatively quickly." At the same time, Burns stressed that responsibility rests with Hamas. "We see the residents of Gaza as the victim of poor leadership of Hamas," he said. "Obviously we do not believe that Hamas has shown the proper degree of leadership in this crisis." Burns said it was "important to remember that Israel was subjected to rocket attacks from Gaza. These were objectionable," he said. "They should not happen, they should stop completely, and the US is consistent in saying that Israel does not deserve to be subjected to these kinds of rocket attacks." Sheera Claire Frenkel and AP contributed to this report.