There is no let-up in Israeli air strikes in Gaza, a UN official has told the BBC, after visiting a hospital struggling to treat the injured.

Gemma Connell of the UN humanitarian agency Ocha told the BBC what she had seen at the Al-Aqsa hospital in central Gaza on Monday was "absolute carnage".

Many severely injured people could not be treated because the hospital was "absolutely overloaded", she said.

Israel's prime minister earlier vowed to intensify the fight against Hamas.

Benjamin Netanyahu said he had visited Gaza on Monday morning and that Israel's military campaign there was "not close to being over".

His comments come days after US Secretary of State Antony Blinken said Israel should lower the intensity of its strikes.

In another development, the Pentagon says the US armed forces have carried out air strikes in Iraq against "Iranian-sponsored militias" in response to an attack on the Irbil air base that injured three US military personnel, one of them critically.

Defense Secretary Lloyd Austin said the strikes had targeted three facilities used by the Iranian-backed Kataeb Hezbollah group and its affiliates.

He said there had been a series of attacks by the militias on US bases in both Iraq and Syria, and stressed that the US would not hesitate to protect its people and facilities.

There has been an escalation of activity by Kataeb Hezbollah and other armed militias in the region following Israel's military operation in Gaza.

Tom White, Director of the UN Agency for Palestinian Refugees UNRWA, told the BBC World Service's Newshour programme that there were currently an estimated 150,000 people in central Gaza who had received evacuation orders from the Israeli military.

Also speaking to the Newshour, Ms Connell said: "What I saw at the Al-Aqsa Hospital in [the city of] Deir al-Balah was absolute carnage."

There were, she said, many casualties there with "extremely severe wounds but [who] cannot be treated because there are so many people in front of them in the line for surgery, and the hospital is absolutely overloaded."

"And some of those that I saw were people who were hit in the strike yesterday [Sunday]," she said in reference to a reported attack on the Al-Maghazi refugee camp in central Gaza.

The Hamas-run health ministry says at least 70 people were killed in the Israeli strike.

The Israel Defense Forces (IDF) said it had received "reports of an incident in the Maghazi camp". It added that "despite the challenges posed by Hamas terrorists operating within civilian areas in Gaza, the IDF is committed to international law including taking feasible steps to minimize harm to civilians".

The injured in Maghazi were taken to Al-Aqsa Hospital, Deir al-Balah, in the central Gaza Strip

Ms Connell also said that while she was visiting Al-Aqsa "there there were new air strikes hitting areas around the hospital in the middle area and new casualties being brought in".

"Tragically I saw a nine-year-old boy with a devastating head injury who passed away," she added.

"When I say that there were strikes again today and casualties arriving, some of those strikes were in areas that people have been told to evacuate to, which, again goes back to the refrain that, I think, I am so sick of saying: that there is no safe place in Gaza," she said.

"And even when people are told to evacuate the places that they are fleeing to are not safe."

The war began on 7 October after Hamas led a deadly attack on communities inside Israel, killing 1,200 people, mainly civilians, and seizing about 240 hostages. Israel says 132 are still being held.

Gaza's Hamas-run health ministry said on Monday that some 20,674 Palestinians had been killed in Israeli bombardments since then. Most of the fatalities are said to be children and women.

Israeli and Arab media say that Egypt has proposed a plan for a ceasefire between the two sides.

According to reports, the plan would see the phased release of all Israeli hostages and an undetermined number of Palestinian prisoners held in Israeli jails over the course of a month and a half, ending with a suspension of Israel's offensive.

A previous temporary truce deal negotiated by Qatar saw dozens of hostages released from Gaza in exchange for Palestinian prisoners.

So far, both Israel and Hamas have resisted growing calls for a ceasefire.