The United Nations Office for Humanitarian Affairs and a health agency warned that any Israeli incursion into the city of Rafah in the southern Gaza Strip could lead to a “massacre” and exacerbate the humanitarian catastrophe in the region.

The city is currently being used as a base for humanitarian operations inside Gaza after months of heavy Israeli bombing and civilian casualties.

Earlier this week, Israeli Prime Minister Benjamin Netanyahu said he would proceed with a ground operation in Rafah regardless of any potential truce agreement with Hamas.

With more than 1.2 million people crowded into Rafah, the city's faltering health system cannot withstand potential devastation if Israel makes an incursion into the area.

Jens Laerke, spokesman for the United Nations Office for the Coordination of Humanitarian Affairs, warned at a press conference in Geneva that hundreds of thousands of residents in Gaza would face imminent danger of death in the event of an attack.

"There could be a massacre of civilians and an incredible blow to the humanitarian operation in the entire sector," he said.

The border city is a vital entry point for humanitarian aid. Dozens of relief organizations are stockpiling supplies for civilians throughout the Gaza Strip such as food, water, health, sanitation and hygiene supplies in southern Gaza City.

For its part, the World Health Organization said that it is preparing contingency plans in the event of an incursion to ensure the health system’s readiness and ability to continue providing care, but these plans will only be “first aid,” according to Rick Pepperkorn, the World Health Organization’s representative in the Palestinian Territory in West Bank and Gaza, in a briefing via video link.

The WHO official warned that the ground military operation would lead to a new wave of displacement, more overcrowding, reduced access to basic food, water and sanitation “and certainly more disease outbreaks.”