The United Nations World Food Programme (WFP) has described the situation in the Gaza Strip as "dire" and warned that vital supplies are dangerously low after Israel imposed a total blockade of the area.

The situation in Gaza is currently "catastrophic", WFP Palestine director Samer Abdel-Jaber said in an interview on Tuesday.

Fuel, water and electricity are in short supply. We see that our emergency shelters are overcrowded. we don't have the capacity.

He added:

The bakery will not be able to provide tomorrow's food. Tomorrow will be very difficult for both those in shelters and those outside of shelters.

"Food and water are in short supply in Gaza and are running out quickly, which is a dire situation," Brian Lander, WFP deputy director for emergencies, told Reuters.

We are providing food to thousands of people sheltering in schools and other locations across the territory. However, it quickly runs out.

He called on Israel and Egypt to establish safe passage for temporary workers to bring aid to Gaza and to ensure that United Nations staff could work safely in the region.

We witnessed a number of facilities considered to be humanitarian, clinics and schools affected by the attacks. We therefore reiterate our call on parties to the conflict to comply with their obligations under international humanitarian law.

Fuel for Gaza's hospital generators will soon run out, the International Committee of the Red Cross (ICRC) said, adding that supplies of aid and medicine were stuck in Gaza due to a lack of safe passage.

Israel's Energy Minister Israel Katz said earlier today that no electricity, water or fuel would be allowed into Gaza until the Israeli hostages returned home.