Israeli military forces have taken control of the Palestinian side of the Rafah crossing between Gaza and Egypt, Israeli officials have said, in the first stage of what appears to be a wider offensive targeting Hamas in the southernmost parts of Gaza. “This is the beginning of our mission to take out the last four Hamas brigades in Rafah. You should be in no doubt about that whatsoever,” an Israeli government spokesperson said. Earlier on Tuesday, a spokesperson for the Gaza border authority confirmed the presence of Israeli tanks at the Rafah crossing and images released by the Israel Defense Forces (IDF) showed tanks flying large Israeli flags driving through the post. Aid officials in the territory said the flow of aid through the crossing, one of the main supply routes for the effort to avert a famine, had been halted. António Guterres, the UN secretary general, called for crossings into Gaza to be reopened immediately, and urged Israel to “stop any escalation”. “Things are moving in the wrong direction. I am disturbed and distressed by the renewed military activity in Rafah by the Israel Defense Forces,” he said. “The closure of both the Rafah and Kerem Shalom crossings is especially damaging to an already dire humanitarian situation. They must be reopened immediately.” The Israeli operation was launched hours after after an announcement by Hamas leaders on Monday night that they would accept a recent proposal for a ceasefire deal that would lead to the release of hostages held by the Islamist militant organisation in Gaza. Israeli officials said they would send a delegation for further talks but accused Hamas of “grandstanding”. The spokesperson said: “Hamas’ proposal is far from Israel’s core demands. Nevertheless, Israel will dispatch a ranking delegation to Egypt to maximise any chance of an agreement on terms acceptable to Israel. Israel is committed to pursuing every avenue, diplomatically and militarily to get our people home.” Hamas said in a statement on Tuesday that Israel’s seizure of the Rafah crossing aimed to undermine ceasefire efforts. The prospect of continued talks left a glimmer of hope for an agreement that could bring at least a pause to the seven-month war that has devastated Gaza. Rafah’s Kuwaiti hospital said on Tuesday that 11 people had been killed by airstrikes overnight and dozens of others injured. The Israeli military said it had targeted Hamas in the city. After vowing for weeks to push into the southern border city, Israel on Monday called for Palestinians in several neighbourhoods in eastern Rafah to leave for an “expanded humanitarian area” to the west and north of the city before a ground incursion. An Israeli military official said the target of the operation in Rafah was “terrorist infrastructure”, after rockets were launched from the crossing at Israeli troops at the nearby Kerem Shalom crossing earlier this week. There were further rocket barrages against the same target on Tuesday, he said. The Rafah crossing is particularly sensitive for Egypt, which is anxious to avoid a mass migration of Palestinians into its Sinai desert in the event of a major offensive into the city, which lies just to its west. A permanent presence at the crossing would give Israel the ability to control all traffic, including aid shipments, and could act as a launchpad for further operations against the cross-border tunnels which, Israeli officials have said, allow Hamas to obtain vital supplies. The more than 1 million Palestinians taking refuge in Rafah have been thrown into confusion with Israel’s evacuation order triggering an exodus of thousands of people. In a phone call on Monday, the US president, Joe Biden, pressed Benjamin Netanyahu, Israel’s prime minister, not to go ahead with a large-scale offensive. Biden has been vocal in his demand that Israel not undertake a ground offensive in Rafah without a credible plan to protect Palestinian civilians. Matthew Miller, a US state department spokesperson, said the US had not seen such a plan, adding that Washington could not support an operation in Rafah as it was envisioned. It was not immediately clear if the proposal Hamas agreed to was substantially different from one that Antony Blinken, the US secretary of state, pressed the group to accept last week and which he said included significant Israeli concessions. Talks in Cairo had appeared to stall at the weekend over Hamas’s insistence that Israel should commit to making the ceasefire permanent at the outset of the agreement, rather than to negotiate its duration after the truce had taken hold. Reports suggest that the deal Hamas agreed to does not include an immediate permanent end to hostilities, but involves three consecutive phases, with different ratios for exchanges of Palestinian prisoners in Israeli jails for hostages and a series of staged withdrawals of Israeli forces from zones of Gaza. Further negotiations could take many days or even weeks, analysts said. Netanyahu’s grip on power might slip if he loses support of far-right coalition allies who oppose any concessions to Hamas, but there is also pressure to free the remaining hostages. The Hostages and Missing Families Forum, an umbrella group, said it had appealed to a number of countries to “exert influence on the Israeli government” and push for an agreement. “At this crucial moment, while a tangible opportunity for the release of the hostages is on the table, it is of the utmost importance that your government manifest its strong support for such an agreement,” the group said in a message sent to the ambassadors of all countries with citizens among the hostages seized by Hamas during its surprise attack into Israel on 7 October. “This is the time to exert your influence on the Israeli government and all other parties concerned to ensure that the agreement comes through which will finally bring all our loved ones home.” Abu Ubaida, a spokesperson for Hamas’s armed wing, al-Qassam Brigades, said in a statement on Tuesday that a 70-year-old Israeli hostage died after she succumbed to wounds from Israeli shelling. There was no independent confirmation of the claim.