The UN agency providing aid to Palestinian civilians in besieged Gaza warned it may have to shut down operations shortly if no fuel reaches the enclave, amid an increasingly desperate need for shelter, water, food and medical services.

The United Nations agency for Palestinian refugees (UNRWA) said it urgently needed fuel to maintain life-saving humanitarian operations in Gaza that has been under Israeli bombardment for almost three weeks.

“If fuel is not received into Gaza, UNRWA will be forced to significantly reduce and in some cases bring its humanitarian operations across the Gaza Strip to a halt. The coming 24 hours are very critical,” it said.

Israel has refused to let in fuel with aid shipments, saying it could be seized by Hamas.