Four days after heavy rains inundated large swaths of the Gaza Strip, the Palestinians are living in an extremely dire condition, UN humanitarians said on Wednesday.

The UN Office for the Coordination of Humanitarian Affairs (OCHA) said the situation continues despite efforts by the United Nations and its partners to reach people in need following the Friday rains.

OCHA said the latest estimates show that more than 18,600 households were impacted, while thousands lost their shelters or were again displaced.

"This number continues to increase as partners complete additional assessments to gauge the extent of the damage caused by the storm," the office said.

As winter draws near, OCHA said its partners working on shelter warned that the volume of items entering Gaza is insufficient to meet people's immense needs.

The office said that since shelter supplies were allowed into Gaza in September following a six-month ban, the world body, its partners and UN member states have brought in 60,000 tents, 346,000 tarpaulins and 309,000 bedding items. Hundreds of thousands of people require urgent shelter support as winter approaches.

OCHA said that as part of the winterization response, its partners focusing on child protection have distributed 48,000 children's winter clothing kits across the strip since the ceasefire came into effect on Oct. 10.

The office said its partners working on nutrition note a gradual decline in the number of patients admitted for malnutrition treatment over the past two months, with approximately 9,280 cases admitted last month, compared with more than 11,740 in September. However, October's numbers are still nearly four times higher than they were in January.

OCHA said that its partners leading water and sanitation efforts reported that over the past two days, they have distributed diapers, towels, jerry cans and other critical items to meet the hygiene needs of 400,000 people.

"However, they warn that sanitation and hygiene conditions in Gaza are deplorable, with no wastewater treatment capacity in the strip due to widespread destruction of infrastructure after two years of war," OCHA said.

The office said the Sheikh Radwan garbage ponds in Jabalya in the north are at risk of overflowing due to the rains. Partners could only provide short-term solutions by discharging sewage into the sea.

"The dilapidated state of Gaza's sanitation systems puts public health at risk, including by raising the threat of bacterial infections spreading through contact with contaminated waste or water," OCHA said.

The office continues to call for items currently restricted from entry into Gaza, including equipment to rehabilitate critical infrastructure, to be allowed into the strip.

OCHA also reiterates the need for nongovernmental organizations to be permitted to bring assistance into Gaza, and for the opening of additional crossings and routes to enable the UN and its partners to reach people in need faster and more efficiently.