Israel bombed southern Gaza Saturday as the UN warned the besieged Palestinian territory has been rendered "uninhabitable" by three months of war.

Top Western diplomats were in the region as part of a fresh push to boost the flow of aid into Gaza and address mounting fears of a wider conflict.

The fighting, triggered by the October 7 attacks on southern Israel by Hamas militants, has sent tensions soaring across the region, and shows no signs of abating with the conflict entering its fourth month on Sunday.

Civilians in the Hamas-ruled Gaza Strip have borne the brunt of the violence as the scale of the destruction has triggered mass displacement and a deepening humanitarian crisis.

With swathes of the territory already reduced to rubble, UN humanitarian chief Martin Griffiths said "Gaza has simply become uninhabitable".

AFP correspondents reported Israeli strikes on the southern city of Rafah, where hundreds of thousands of people have sought shelter from the fighting.

On Israel's northern border, Lebanon's Hezbollah group said it launched its "initial response" to the killing of Hamas's deputy leader in Beirut.

A US defence official has told AFP that Israel carried out the strike, which Israel has not claimed.

The Iran-backed group said it had targeted the Israeli military's Meron air control base with 62 missiles, while the Israeli army reported "approximately 40 launches from Lebanon" early Saturday, and said it struck Hezbollah "military sites" in response.

By the afternoon, warning sirens had sounded seven times in northern Israel, the military said.

Contacted by AFP, a military spokesperson confirmed the mountaintop base had been targeted but did not say whether it was damaged. No casualties were reported in Israel.

The Hamas-allied Lebanese movement has been trading near-daily fire with Israeli forces since early October and said the barrage was a response to Tuesday's killing of Saleh al-Aruri in a strike on Beirut's southern suburbs, a Hezbollah stronghold.

While the two sides exchanged fire on Saturday, European Union foreign policy chief Josep Borrell, on a visit to Beirut, warned against a wider war.

"It is imperative to avoid regional escalation in the Middle East. It is absolutely necessary to avoid Lebanon being dragged into a regional conflict," Borrell said.

Before heading to Saudi Arabia, Borrell called for a redoubling of peace efforts.

"Israel has declared a goal to eradicate Hamas. There must be another way to eradicate Hamas that doesn't… create so many people getting killed," he said.

In the central Gaza town of Deir al-Balah, men clambered carefully around the concrete ruins and twisted rebar where Mohammad al-Attar's house stood before rockets that he blamed on Israel destroyed it.

"There was no prior warning or anything," Attar said, his hands stained grey from the debris. "There's still the corpse of a little girl" underneath.

'More than 20' deaths in family

The war began with Hamas's unprecedented attack which resulted in the deaths of around 1,140 people in Israel, most of them civilians, according to an AFP tally based on official figures.

The militants also took around 250 hostages, 132 of whom remain in captivity, according to Israel, including at least 24 believed to have been killed.

In response, Israel is carrying out a relentless bombardment and ground invasion that have killed at least 22,722 people, most of them women and children, according to the Gaza health ministry.

In a statement on Saturday, the ministry said it had recorded more than 120 deaths over the past 24 hours.

Victims of renewed Israeli bombardment were brought to the European Hospital in the southern city of Khan Yunis, where relatives and mourners gathered.

One of them, Mohamed Awad, wept over the body of a 12-year-old boy and counted the deaths in his family. 

"My brother, his wife, his children, his relatives and the brothers of his wife — there are more than 20 martyrs," Awad, a journalist, told AFP.

Another Palestinian journalist, Akram El-Shafei, died at the hospital from wounds sustained in Gaza City in November, making him "the 117th journalist… killed by the Israeli occupation during this crazy war", Asser Yassin of the Palestinian Media Forum said.

Yassin charged that Israel "targets journalists" but that "only increases our determination to… convey the suffering and pain" to the world.

Israeli officials have repeatedly denied that the army deliberately targets those working for the media.

Shafei's condition had initially improved, said relative Magda El-Shafei, but he "needed treatment" and there was "nothing" available. 

"He's gone," she told AFP.

The World Health Organization says the majority of Gaza's 36 hospitals have been put out of action by the fighting, while remaining medical facilities face dire shortages.

Diplomatic push

US Secretary of State Antony Blinken was in Turkey on the first leg a tour that will take him to Greece and several Arab states ahead of talks in Israel and the occupied West Bank next week.

A senior US administration official said Blinken would press Israel to increase aid to Palestinians and move to a combat phase that allows the displaced to start returning home.

Much of the discussions with Arab leaders will focus on containing the violence and looking at how Gaza can be governed once the fighting ends, said the US official, whose country is Israel's biggest political and military backer.

in a video message shared by his office, Hamas leader Ismail Haniyeh, said that "the future and stability of our region are closely linked to our Palestinian cause."

The secretary general of the Palestine Liberation Organisation executive committee, Hussein al-Sheikh, said Gaza's future "is determined by the Palestinian people, not Israel."

He was responding to Israeli Defence Minister Yoav Gallant's release on Thursday of a draft plan for Gaza's post-war governance that spoke of Palestinian "civil committees" taking gradual control, while Israel would "reserve its operational freedom of action" throughout the territory.