A senior Israeli official has said he expects the war against Hamas in Gaza to continue for at least the rest of this year.
"We are expecting another seven months of fighting,” the prime minister’s national security adviser, Tzachi Hanegbi, told Israel's Kan public radio.
He also said Israel’s military had taken control of 75% of the buffer zone along the Gaza-Egypt border, as it pressed ahead with an assault on the southern city of Rafah.
Residents of Rafah meanwhile reported that there had been more Israeli air strikes and that tanks had mounted raids in central and western areas before retreating.
A senior World Health Organization (WHO) official also warned that Rafah’s last hospital was barely functional and that a "full incursion" by Israeli troops could lead to its closure and a "substantial" number of deaths.
The Israel Defense Forces (IDF) said on Tuesday that troops were operating in a “very targeted” way against Hamas’s remaining battalions in Rafah, from which more than one million Palestinians have fled over the past three weeks.
The US government also said it did not believe “a major ground operation” was under way, which could trigger a change in its policy on military aid to Israel.
Israel has insisted that it must take Rafah to achieve victory in the war triggered by Hamas’s unprecedented attack on the country on 7 October, during which about 1,200 people were killed and 252 others were taken hostage.
At least 36,170 people have been killed across Gaza since the start of the conflict, according to the Hamas-run health ministry.
The suggestion from Mr Hanegbi - seen as a close confidant of Israeli Prime Minister Benjamin Netanyahu - that the conflict could go on for at least another seven months will worry many in Israel and outside.
There has been growing international pressure on Israeli leaders to outline a full strategy to end the fighting and a convincing post-war vision for the Palestinian territory.
In his interview, Mr Hanegbi also suggested that Israel would soon take full control of the Philadelphi Corridor - a buffer zone, only about 100m (330ft) deep in parts, which runs along the Gaza side of the 13km (8-mile) border with Egypt.
"Inside Gaza, the IDF is now in control of 75% of the Philadelphi Corridor and I believe it will be in control of it all with time,” he said.
The plan, he added, was to work with the Egyptians to “ensure weapon smuggling is prevented”.
Egypt has denied weapons are still being smuggled under the border. But the IDF said on Tuesday that it was demolishing tunnels that led to the Sinai peninsula.
Residents have said that troops have seized about 9km of the Philadelphi Corridor, including the Rafah border crossing, since the start of the ground operation in Rafah on 6 May.
The troops have also gradually pushed into built-up neighbourhoods of Rafah city from the east and south, and reportedly reached the central al-Awda roundabout on Tuesday.
On Wednesday, residents told Reuters news agency that tanks advanced into western Tal al-Sultan and central Yibna and Shaboura areas before pulling back towards positions on the border.
The IDF also announced that three Israeli soldiers were killed in combat in Rafah on Tuesday.
Meanwhile, Gaza’s Hamas-run health ministry warned the Israeli bombardment of Rafah was making it increasingly difficult for patients and health teams to reach the Emirati maternity hospital in Tal al-Sultan.
It came a day after the WHO said the hospital was barely functional and could no longer accept patients.
“If the incursion would continue, we would lose that last hospital in Rafah,” Dr Rik Peeperkorn, the agency’s representative for Gaza and the occupied West Bank, warned in an interview with Reuters and AFP news agencies in Geneva.
With the European Gaza Hospital in the city of Khan Younis inaccessible because of Israeli evacuation orders and fighting on the ground, the estimated 1.9 million people in southern Gaza would be left “dependent on a string of field hospitals along the coast”, he said.
Dr Peeperkorn said there was a contingency plan to refer patients to al-Aqsa hospital in the central town of Deir al-Balah and to restore services to two other hospitals in Khan Younis which were raided by Israeli forces. But, he added, if there was a “full incursion”, the plan would “not prevent what we expect substantial additional mortality and morbidity”.
All the field hospitals still functioning in the Rafah area are overwhelmed by casualties and undersupplied, according to the WHO.
The Palestine Red Crescent Society (PRCS) said on Wednesday that it had evacuated the al-Quds field hospital in al-Mawasi, a coastal area just to the north-west of Rafah.
“This action was taken due to the increased threat level from the Israeli occupation, continued artillery and air bombardments in its vicinity, and the complete evacuation of residents from the surrounding area,” a statement explained.
On Tuesday, Gaza’s health ministry said six other medical facilities in Rafah - al-Najjar hospital, the Kuwaiti Specialist hospital, the two Rafah field hospitals, the Indonesian field hospital, and the Abu al-Walid Central Clinic - had been forced out of service.
Al-Najjar hospital, Rafah’s largest, was evacuated at the start of the Israeli operation, while the Medical Aid for Palestinians (MAP) said the smaller Kuwaiti hospital closed “after an Israeli tank attack outside the hospital killed two medical staff” on Monday.
Separately, WHO spokeswoman Dr Margaret Harris said the casualties from an Israeli air strike and resulting fire at a camp for displaced people in the Tal al-Sultan on Sunday had “absolutely overwhelmed” field hospitals in southern Gaza.
The health ministry said at least 45 people were killed in the incident. Hundreds more were treated for severe burns, fractures and shrapnel wounds.
IDF spokesman Rear Adm Hagari said on Tuesday that aircraft had targeted two senior Hamas officials inside a structure that was away from any tents, using “two munitions with small warheads”.
“Our munitions alone could not have ignited a fire of this size,” he said, adding that the military was looking into the possibility that weapons stored by Hamas nearby could have caused a secondary explosion.
On Tuesday, Palestinians accused Israel of shelling tents at al-Mawasi, where it had advised civilians in Rafah to go for safety. But the IDF said it “did not strike in the humanitarian area in al-Mawasi”.
Last week, the International Court of Justice (ICJ) ordered Israel to “immediately halt its military offensive, and any other action in the Rafah Governorate, which may inflict on the Palestinian group in Gaza conditions of life that could bring about its physical destruction in whole or in part”.