In a statement, UN Emergency Relief Coordinator Martin Griffiths described the scale and speed of the unfolding crisis as “bone-chilling”.

UN agencies have been working round the clock since Hamas and Palestinian Islamic Jihad launched an attack on Israel four days ago, prompting intensive strikes by Israel and a complete siege of the Gaza Strip.

Uphold the laws of war

Mr. Griffiths outlined the toll on both sides.

He said hundreds of Israelis have been killed and thousands injured. Scores are also being held captive “facing appalling threats to their lives.”

Meanwhile, hundreds of Palestinians have also been killed and thousands injured in intense bombing in Gaza. He noted that homes, health centres and schools sheltering displaced families have been hit.

“My message to all sides is unequivocal: The laws of war must be upheld,” he said “Those held captive must be treated humanely. Hostages must be released without delay.”

Mr. Griffiths stressed the need to protect civilians and civilian infrastructure.

“Civilians must be allowed to leave for safer areas. And humanitarian relief and vital services and supplies to Gaza must not be blocked,” he said.

Food assistance for Gaza

The World Food Programme (WFP) on Tuesday launched an operation to provide critical food assistance to more than 800,000 people in Gaza and the West Bank.

WFP called for establishing humanitarian corridors to facilitate the entry of aid and humanitarian assistance into Gaza, while appealing for the safe and unobstructed passage for its staff and essential commodities.

More than two million people live in the enclave and at least 200,000 have been displaced. Most are now sheltering in schools run by the UN agency that assists Palestine refugees, UNRWA.

WFP urgently requires access and funding to reach those in need and is seeking $17.3 million in the next four weeks to address this critical situation.

UN Humanitarian Coordinator for the Occupied Palestinian Territory, Lynn Hastings, said Israel had cut water supply to Gaza, which was already experiencing scarcity.

Access to electricity, food, and fuel have also been severed, worsening the already dire humanitarian situation resulting from more than 15 years of blockade.

Electricity is now only available for roughly four hours a day, which hinders the ability of health facilities to function and treat those injured.

“The United Nations and its humanitarian partners in the Occupied Palestinian Territory are working to meet acute needs, in particular shelter, in dangerous circumstances. However, access for humanitarian staff and supplies into Gaza has also been cut and the intensity of the hostilities is limiting the ability of staff to deliver aid,” she said.