Hospitals and medical facilities have become caught up in intense fighting as Israel presses its offensive against Hamas in Gaza City.
The focus of attention has been on Al-Shifa, Gaza's largest hospital, where an estimated 2,300 people remain trapped by battles in the surrounding streets.
Other facilities are reporting similar situations - a lack of supplies and power, and an ever-present threat to life due to fighting.
Israel says it is not targeting hospitals directly but acknowledges there are "clashes" around Al-Shifa and other facilities.
The World Health Organization (WHO) says 36 health facilities including 22 hospitals have been damaged since the war began on 7 October, and only a handful are now still operational.
Here is what the BBC knows about the situation at the main facilities in northern Gaza.
Al-Shifa hospital, Gaza City
The WHO said on Sunday that Al-Shifa in Gaza City - the territory's largest with 700 beds - had ceased to function and that the situation inside was "dire and perilous".
The surrounding streets are engulfed by fighting between Hamas and Israeli forces. Critical infrastructure has been damaged, according to the UN.
Israel says Hamas fighters operate in tunnels underneath the hospital - a claim which Hamas denies.
Staff inside say it is impossible to leave without risking injury or death.
The WHO director general, Tedros Adhanom Ghebreyesus, said on X that "constant gunfire and bombings in the area have exacerbated the already critical circumstances".
Multiple reports from inside say there is no food and no fuel to run generators. Solar energy is being used to power a few critical systems.
There have been communication blackouts - the Doctors Without Borders charity was unable to contact its members inside Gaza over the weekend. Attempts by the BBC to contact workers have often been unsuccessful.
The Hamas-run health ministry has said there are at least 2,300 people still inside the hospital - up to 650 patients, 200 to 500 staff and around 1,500 people seeking shelter.
This number includes new-born babies being kept in a surgical theatre at the site.
Staff say that three of 39 infants in their care died over the weekend due to there being no incubators. Surviving babies were at serious risk of death, according to doctors.
The Israel Defense Force's (IDF) chief spokesman, Rear Admiral Daniel Hagari, said on Saturday that Israel would provide assistance to evacuate the babies to a "safer hospital".
However, that evacuation is yet to happen as of Monday morning.
Hospital staff have told the BBC that moving the babies safely would require sophisticated equipment, and that there is no "safer hospital" inside Gaza.
On Saturday, Colonel Moshe Tetro of the IDF, said there were clashes nearby, but no shooting at the hospital itself, and no siege.
Anyone who wanted to leave, he said, could do so. He insisted that to say otherwise was a lie.
Marwan Abu Saada, a surgeon in Shifa, told the BBC that there was bombing around the hospital and ambulances could not get in.
The IDF also said efforts to deliver 300 litres of fuel to Shifa on Sunday failed because Hamas refused to accept it - something Hamas denied.
Mr Abu Saada told the BBC on the same day that 300 litres would "last 30 minutes" - the hospital needs 10,000 litres a day to operate normally.
Additional to this is the growing risk of disease due to a lack of sanitation, and the decomposition of dead bodies that can not be refrigerated.
Mr Abu Saada said that attempts to bury the dead had been thwarted by fighting around the complex, and the morgue refrigerator had failed due to a lack of power.
There were 100 bodies unburied in the hospital courtyard, he added.
Israel asserts that there is a Hamas command centre underneath Shifa - IDF spokeswoman Libbu Weiss said: "We know that with certainty. We've shared significant information that speaks to that."
It has shared a 3-D representation of what it claimed were a network of tunnels under the hospital, and recordings it says are of Hamas fighters discussing them.
Hamas denies it is using the hospital or that it has an operations centre underneath. Doctors inside insist there is no Hamas presence there.
The BBC's Gaza correspondent Rushdi Abdalouf said that he had never seen "any military capability" inside the hospital, but acknowledged it was difficult to verify either Israel's or Hamas's claims.
Al-Quds hospital
The Gaza Strip's second largest hospital after Al-Shifa has, according to the Palestinian Red Crescent, ceased to be operational.
The Palestinian Red Crescent said on Saturday that its teams were trapped inside with 500 patients and around 14,000 displaced people, mostly women and children.
On Sunday it stated that the hospital was "out of service... no longer operational... due to the depletion of available fuel and power outage".
"Medical staff are making every effort to provide care to patients and the wounded, even resorting to conventional medical methods amid dire humanitarian conditions and a shortage of medical supplies, food, and water.
"The hospital has been left to fend for itself under ongoing Israeli bombardment, posing severe risks to the medical staff, patients and displaced civilians."
Doctors Without Borders said on Saturday it had lost contact with a surgeon working and sheltering in Al-Quds with his family.
A spokesman for the Red Crescent told Reuters that the hospital had been cut off for nearly a week, with "no way in, no way out", and the surrounding area was under constant attack.
Al-Rantisi and al-Nasr, northern Gaza City
The small Rantisi Specialised Hospital for Children and the nearby Al-Nasr hospital, in the north of Gaza City, were evacuated on Friday save for a handful of patients and staff. Rantisi had Gaza's only paediatric cancer ward.
The IDF released to the BBC details of phone conversations between an official at Rantisi and a senior officer in the IDF, in which they discuss arrangements to get ambulances to evacuate patients.
The hospital official asks about hundreds of displaced civilians camped out at the two hospitals. The Israeli officer tells them to leave via the main entrance at 11:20 and explains in detail which streets they should walk along to leave Gaza City.
And he twice tells the hospital official to make sure civilians are carrying something white to show they are not combatants.
"They will all go out with their hands in the air," the hospital official says. "Perfect," the Israeli says.
Dr Bakr Gaoud, the head of Rantisi, was quoted by the New York Times as saying that Israeli forces arrived at the end of last week and provided maps showing a safe way out.
"We dragged our patients out of their beds," he said, adding that the patients in the worst condition were sent to Al-Shifa, which was already overwhelmed and ceasing to function.
Everyone else, he said, made their way to southern Gaza away from the main fighting.
Al-Sweidi (the Swedish) clinic, Shati camp
The UN's office for humanitarian affairs said in its Saturday update that the Swedish clinic had been "hit and destroyed" by an air strike.
There were around 500 people sheltering there it reported, and the casualty toll was "unclear".
On Monday, BBC Gaza correspondent Rushdi Abdalouf spoke to a survivor, Maryam al-Arabeed, 65, who told the BBC that Israeli soldiers entered the facility on Sunday night, moved everyone out and watched "an Israeli bulldozer completely demolish the building".
"They took the young men out including my three sons and separated the women and children," she told the BBC.
The International Committee for the Red Cross said in an update on Sunday that it was "paramount that members of the same family are not separated during evacuations".
Ms Arabeed said that she was forced to sleep in the street and then "me plus six women, and a number of children walked away" in the morning.
"The Israeli army asked us to enter Al-Shifa Hospital, and now I am in the hospital and I do not know where my sons and relatives are," she said.
"Tanks were shooting above our heads and they asked us not to look to the right or left."
Indonesia Hospital, Jabaliya
Staff at this Indonesian-funded hospital in Jabaliya said on Saturday that it was still operational despite suffering damage and running out of fuel and supplies.
In an open letter on Saturday, Sarbini Abdul Muradm - the chairman of the group which runs the hospital, said that it "was trying to survive and operate amid darkness and a shortage of medications".
He said the hospital was "the only hope for the people of north Gaza to seek refuge and access medical treatment".
Indonesia on Friday said parts of the building had been damaged by overnight explosions nearby. It did not report any casualties.
On Sunday, the Reuters news agency shared video of doctors at this hospital working by torchlight to treat a baby.
The number of people still inside is unknown.
Muhammad Qandil, a doctor at Nasser hospital in Khan Younis, southern Gaza, said his contacts at the Indonesian hospital reported suffering the same shortages of fuel and medical supplies and urged for safe passage of those who were inside.