The UN World Food Programme (WFP) warned on Monday that crucial supplies were running dangerously low in the Gaza Strip after Israel imposed a total blockade on the territory following deadly Hamas attacks.

“It’s a dire situation in the Gaza Strip that we’re seeing evolve with food and water being in limited supply and quickly running out,” said Brian Lander, the deputy head of emergencies at WFP.

“WFP is on the ground and is responding and we’re providing food to thousands of people that have sought shelter in schools and elsewhere across the territory. But we’re going to run out very soon,” he told Reuters TV.

Israel announced a total siege on Gaza on Monday, blocking the entry of food, fuel and water into the coastal territory and shuttering all crossing points following Hamas’s weekend rampage that killed more than 1,300 people.

The International Committee of the Red Cross (IRCRC) said on Thursday that fuel for hospital generators in Gaza would run out shortly, adding that its stocks of aid and medicine within Gaza were stranded for want of safe passage.

Besides sealing the border, the Israeli military has also launched massive air attacks on the enclave, forcing hundreds of thousands of Palestinians to flee their homes.

“The people that are seeking shelter and striving to survive in this environment are only going to get into worse and worse situations as time goes on,” Lander said.

Hostages for aid: Israel

Israel on Thursday said nothing would be allowed into Gaza until Hamas militants freed some 150 hostages taken during their deadly weekend incursion.

“Not a single electricity switch will be flipped on, not a single faucet will be turned on, and not a single fuel truck will enter until the Israeli hostages are returned home,” Israeli energy minister Israel Katz said on social media.

Lieutenant Colonel Richard Hecht, an Israeli military spokesman, said forces “are preparing for a ground maneuver” should political leaders order one.