There is a plausible case that Israel is using starvation as a weapon of war. That's according to the United Nations' most senior human rights official, Volkertürk. He says, If proven, that would amount to a war crime. Humanitarian agencies are calling for an immediate ceasefire and large deliveries of aid in Gaza, where a famine is looming. Israel insists it's letting in all the humanitarian aid that is needed. From Jerusalem, here's our international editor, Jeremy Bone, and his report contains upsetting images.

Gaza is no place to be ill. Noura Muhammad had lung and liver problems before the war. Now, after months of starvation and without the right medical care, she is deteriorating fast.

My daughter can't move, says her mother.

She's anemic, always sleeping, and there's nothing nutritious to eat. There is plenty to eat, only a few miles away in the lorries that are backed up on the Egyptian side of the border, and much more that could come from Israel if the Israelis let it into Gaza. From Geneva, Volkertürk, the UN's most senior human rights official, told me there is plausible evidence that Israel is using starvation as a weapon of war.

Look, when it comes to humanitarian assistance, let's be clear. Israel is an occupying power and has an obligation to provide humanitarian assistance. Assistance. And if that humanitarian assistance does not come in in the scale, speed, and predictability that is required, yes, very serious questions are raised.

So let's get it very clear, Israel's to blame.

Israel is to blame in a significant way, yes.

You're aware, of course, that Israel says they're not to blame at all, that they give as much aid as is possible, that if anyone's to blame, it's the UN, and it's particularly Hamas.

It is absolutely clear what happened on the seventh and the eighth of October by Hamas and some of the other armed groups is unconscionable. These are flagrant violations of international humanitarian law and international human rights. At the same time, the brutality of the attack by Israel and the method of warfare. It begs the question of the proportionality of the response.

You're saying questions. You say there's no doubt about Hamas. Are there any doubts about Israel?

You always I have to prove the intent. But as I said, collective punishment, the collective punishment that was declared with the siege, is indeed amounts to a war crime, and it needs to be dealt as such.

On social media, false claims circulate that famine in Gaza is a lie. The Hebrew caption says, There's more shawarma in Gaza than in Israeli Haifa, and Israel's government dismisses the UN's accusations.

Total nonsense. Total responsible thing to say. Israel is accepting all the aid that the US and the world is giving to Gaza innocent people, which a lot of it goes to extend the war.

How many innocent people are in Gaza, in your opinion?

I'm not going to quote any number. I'm basically saying that over 70 % of Gazans support October seventh Massacre.

So they're not innocent?

The people that are supporting Hamas, they have a different thought. They're an enemy. I thank our friends around the world for supporting our strategic goal. And I'm telling you- But they don't like the way you're doing it, do they? That's tough. We're going to finish the war. We'll do everything we can to kill the Hamas terrorists and to minimize collateral damage as much as we can.

The evidence of Gaza's humanitarian catastrophe is overwhelming, and it is deepening international pressure on Israel. Swolen joints, wasted limbs, and dermatitis classic symptoms of acute malnutrition. These children reached hospital. Most of just over one million Gazans considered to be in acute need will not have that option. Jeremy Bowen, BBC News, Jerusalem.