Hamas is blocking foreign nationals including Britons from leaving Gaza, the United States said on Sunday, as Israel sent more troops into the strip to join a ground offensive.

Britain was on Sunday working to rescue trapped citizens as civil disorder and looting broke out at UN aid warehouses in besieged Gaza.

American officials said that Israel and Egypt were prepared to let foreigners leave the Strip which is under heavy Israeli bombardment, but Hamas had refused.

At least 200 British citizens are thought to be registered with the UK authorities inside the coastal enclave, and some 600 Americans, as well as many other nationalities.

Jake Sullivan, the White House’s chief security adviser, said: “The Egyptians are prepared to let Americans and other foreign nationals out of Gaza. The Israelis have no issue with that. But Hamas is preventing their departure and making a series of demands.”

UK Government sources said they shared US concerns that Hamas could block foreign nationals from leaving Gaza unless demands are met, effectively holding them hostage in a war zone.

Last night world leaders raised the plight of trapped foreigners in a series of phone calls as Isreal ramped up its ground offensive.

Rishi Sunak, the Prime Minister, and Emmanuel Macron, the French president, agreed to work together to get British and French nationals out of Gaza and get more aid in.

Joe Biden, the US President, meanwhile again told Benjamin Netanyahu, Israel’s prime minister, that his military must distinguish between Palestinian civilians and Hamas terrorists during Israel’s war to wipe out terrorists.

He also spoke with Egypt’s president to push for more aid and the protection of civilians in Gaza.

The IDF meanwhile continued to expand its armoured push into the Strip sending more troops into the north in what analysts said appeared to be a gradual, probing attack.

As the assault continued, a Palestinian aid group said the major al-Quds hospital had been ordered to evacuate by Israeli authorities.

The World Health Organisation said the threat was “deeply concerning” and repeated warnings that it was impossible to evacuate hospitals without endangering the lives of the patients inside.

As the situation in the Strip became more desperate, thousands of Gazans broke into United Nations warehouses to take flour and hygiene supplies.

Crowds of people were filmed carrying away sacks of flour marked with the blue logo of the UN’s Palestinian refugee agency, UNRWA.

Thomas White, the director of UNRWA affairs in Gaza, said the break-in was “a worrying sign that civil order is starting to break down”.

“People are scared, frustrated and desperate,” he said.

Israel accused Hamas’s leader of being responsible for the devastation of Gaza.

Daniel Hagari, spokesman for the IDF, claimed that the people of Gaza have said Yahya Sinwar “no longer cares” about them.

“He has imposed such a terrible disaster on them,” Rear Admiral Hagari said. “He has lost control and he is the individual responsible for the collapse and devastation of Gaza.”

Mr Sullivan also warned: “Hamas is making life extremely difficult for Israel by taking civilians as human shields and putting their rocket infrastructure and terrorist infrastructure among civilians.”

On Sunday the Hamas-controlled Gaza health ministry claimed the death toll among Palestinians passed 8,000, with most of them women and children.

Aid supplies to Gaza have been minimal since Israel imposed a “total siege” and began bombarding the enclave in response to Hamas’ Oct 7 attack which killed 1,400 Israelis.

Impeding relief supplies to Gaza’s population may constitute a crime under the International Criminal Court’s (ICC) jurisdiction, the court’s top prosecutor has said.

Karim Khan said Israel must make “discernable efforts, without further delay to make sure civilians receive basic foods, medicine”.

Israeli officials have said that food, water and medicines have been coming in through the Egyptian border and that it expected the quantities to rise.

Gunmen ambushed Israeli troops

As the IDF expanded their ground operation in Gaza on Sunday, Hamas gunmen ambushed Israeli troops from tunnels near the Gaza border, the IDF reported.

The IDF said several Hamas terrorists had been killed and others were wounded after they launched an attack from a tunnel near Erez in the northern Gaza Strip.

IDF troops also distributed leaflets instructing Hamas gunmen to raise their hands and wave a white flag when surrendering.

The Israeli military also said on Sunday that its calls on Palestinians in the Gaza Strip to evacuate southward, away from the main focus of the war against Hamas, was now “urgent”.