An Israeli siege has sparked acute shortages of food, water, medicine and fuel in Gaza, where the health system is collapsing, AFP reports.

The head of the UN agency for Palestinian refugees, Philippe Lazzarini, said during a visit to the Gaza Strip on Saturday “the massive death, destruction, displacement, hunger, loss and grief of the last 100 days are staining our shared humanity”.

He warned an entire generation of children in Gaza were being “traumatised”, diseases were spreading and the clock was “ticking fast towards famine”.

Winter rains have exacerbated the dire humanitarian situation in Gaza, where the UN estimates 1.9 million — nearly 85 per cent of the population — have been displaced.

Many have sought shelter in Rafah and other southern areas where the health ministry says there isn’t the infrastructure to support them.