Egypt is moving to avert a mass exodus from the Gaza Strip into its Sinai Peninsula, as Israeli bombardment halted crossings at the main exit point from the Palestinian enclave on Tuesday, Gaza officials and Egyptian security sources said.

Israel’s assault on Gaza has caused alarm in Egypt, which has urged Israel to provide safe passage for civilians from the enclave rather than encouraging them to flee southwest towards Sinai, two Egyptian security sources said.

Egyptian President Abdel Fattah al-Sisi said on Tuesday that the escalation in Gaza was “highly dangerous” and that Egypt was pursuing a negotiated solution to the violence with regional and international partners.

Egypt would not allow the issue to be settled at the expense of others, Sisi said in comments reported by state news agency MENA, an apparent reference to the risk that Palestinians could be pushed into Sinai.

The Rafah border crossing remained shut on Wednesday morning, after Egyptian military planes conducted flights nearby overnight, security sources said. The military has also taken up new positions close to the border, running patrols to monitor the area, said Ahmed Salem of the Sinai Foundation for Human Rights.

Rafah is the sole possible crossing point into Sinai for Gaza’s 2.3 million residents. The rest of the densely populated strip is surrounded by the sea, and by Israel, which has announced a total siege of Gaza and could launch a ground offensive.

The passage of people and goods in and out of Gaza is strictly controlled under a blockade enforced by Egypt and Israel.

On Tuesday, the Israeli military revised a recommendation by one of its spokespeople that Palestinians fleeing its air strikes in Gaza head to Egypt.

Israel has been pounding Gaza with the fiercest strikes in the 75-year history of its conflict with the Palestinians since Hamas launched a deadly incursion into Israel on Saturday.

Mediation role

Egypt, the first Arab country to make peace with Israel, has mediated between Israel and Palestinian factions during previous conflicts in Gaza and has pressed to prevent further escalation in the current fighting.

Gaza’s Hamas-run Interior Ministry said bombardments on both Monday and Tuesday had hit an entry gate on the Palestinian side of the Rafah crossing. The crossing was also closed from the Egyptian side and Palestinians planning to travel to Gaza retreated to north Sinai’s main city of Al Arish, Egyptian sources said.

On Monday, about 800 people left Gaza through the Rafah crossing and about 500 people entered, though the crossing was closed for the movement of goods, according to the United Nations humanitarian office.

North Sinai’s governor met local authorities on Monday to plan for any crises resulting from events in Gaza, his office said, and ambulances have been mobilised in Sinai for possible evacuations from Gaza. So far, there has been no sign of mass gatherings of Palestinians at the Rafah crossing, with only scheduled departures proceeding until Tuesday.

In 2008, tens of thousands of Palestinians crossed into Sinai after Hamas blasted holes in a border wall.

Security in the area around Rafah is also of concern to Egypt because Sinai has been the site of an Islamist insurgency that flared a decade ago. Hamas, which has run the Gaza Strip since 2007, shares the Islamist ideology of the Muslim Brotherhood, a movement outlawed in Egypt.

Egypt’s military has in recent years largely asserted its control over northern Sinai, facing sporadic attacks there.