Live updates: Follow the latest from Israel-Gaza
Israel's military said it had taken into custody 100 people at one of Gaza's main hospitals, suspecting them of being involved in “terrorist activity”.
The army said it seized weapons and retrieved “medications with the names of Israeli hostages” at Nasser Hospital in Khan Younis.
Gaza's Health Ministry confirmed that Israeli troops arrested a large number of medical personnel from inside the hospital, which it said has been turned into a military barracks.
The hospital is still without electricity because generators have been halted, posing a threat to patients requiring oxygen, the ministry said. At least 120 patients and five medical teams are stuck without water, food and electricity.
“Newborn children are at risk of dying in the next few hours,” the ministry warned on Saturday.
Troops are also preventing critical patients from moving from Nasser Hospital to other medical centres, it said.
Meanwhile, Hamas chief Ismail Haniyeh blamed Israel for a lack of progress in achieving a ceasefire deal in Gaza.
Hamas “will not accept anything less than a complete cessation of the aggression, withdrawal of the occupation army from Gaza, and lifting of the unjust siege”, he said.
The Gaza Health Ministry said on Saturday that at least 28,858 people have been killed and 68,667 wounded in Gaza since the war began.
Israel began its air and ground campaign in the enclave on October 7, after Hamas carried out attacks on southern Israeli communities, killing about 1,200 people and taking 240 hostages.
Israeli planes, artillery and naval forces continue to bombard various areas in the Gaza Strip, hitting several buildings, including residential blocks.
Israel renewed its artillery shelling on Saturday morning in Deir Al Balah, central Gaza.
Palestinian media said Israel carried out air and artillery strikes on central residential areas of Gaza city.
Local sources said more than 10 Palestinians were killed when an Israeli shell hit a house in the Sheikh Radwan neighbourhood of Gaza city.
Two other homes were hit in the city's Sabra neighbourhood, while the Zaytoun district was also hit by shelling, Palestinian media reported.
Israeli artillery also struck near Beit Hanoun in northern Gaza.
Gaza city officials said Israel's strikes had “destroyed dozens of municipal buildings”, including administrative offices, markets, commercial shops, cultural centres, and libraries.
Air strikes hit farmland south of Deir Al Balah, as well as the village of Qarara village north of Khan Younis.
One person was killed and at least one injured when an apartment was hit by shelling in the Jeneina neighbourhood of Rafah, southern Gaza.
For weeks, Israel's military operation has been concentrated in Khan Younis, the hometown of Hamas's leader in Gaza, Yahya Sinwar, who Israel says planned the October 7 attacks.
Doctors Without Borders said its medics had been forced to flee and leave patients behind, with one employee unaccounted for and another detained by Israeli troops.
The UN Human Rights Office said Israel's raid on Nasser Hospital appeared to be “part of a pattern of attacks by Israeli forces striking essential life-saving civilian infrastructure in Gaza, especially hospitals”.
Eight killed in Israeli strike on Rafah
Israel has repeatedly accused Hamas of using hospitals for military purposes, which the group denies.
On Saturday, German Chancellor Olaf Scholz warned Israeli leaders to abide by international law in its campaign in Gaza, as the military prepares for a ground incursion into Rafah.
Speaking at the Munich Security Conference, Mr Scholz reaffirmed Germany’s support for Israel’s security, but reaffirmed Berlin's expectation that Israel will respect humanitarian law and the rules of war.
At the same conference, Chinese Foreign Minister Wang Yi called for an “accelerated state of Palestine”, saying “generations of Palestinians have been displaced”.
Recent events proved that “the question of Palestine is at the heart of the Middle East”, he said and spoke of the need to act to protect civilians in Palestine.
The conflict requires a move to a two-state solution, and “co-existence” between the people of Palestine and Israel, he said.
Hamas has warned that hostages held in Gaza are “struggling to stay alive” as conditions deteriorate amid relentless Israeli strikes.
About 130 hostages are still believed to be in Gaza, according to an AFP tally based on official Israeli figures.
Meanwhile, Israel has been exchanging near daily artillery fire across its northern border with Iran-backed Lebanese militia Hezbollah since the war broke out.
Hezbollah leader Hassan Nasrallah has vowed that Israel would pay “with blood” for Lebanese civilians killed in the exchanges and warned that the militia has missiles that can reach anywhere in Israel.
