UNITED NATIONS - Civilian casualties and damage mount in Iran and Lebanon, while displaced families in Gaza grapple with heavy rains damage and impediments to aid delivery persist, UN humanitarians said Thursday.

The UN Office for the Coordination of Humanitarian Affairs (OCHA) said that in Iran, casualties were reported in at least 20 of the total 31 provinces, with the highest numbers reported in Tehran and Hormozgan.

The Iranian Ministry of Health reported that as of Wednesday, 23,000 casualties from the hostilities, including 1,801 children and 4,150 women. The ministry also reported 23 deaths and 112 injuries among health care workers as of Wednesday.

The Iranian Red Crescent Society (IRCS) reported one death and 14 injuries among relief workers as of Thursday. Hostilities have forced people to relocate to safer areas, increasing their vulnerability and often disrupting their access to essential support, basic services and livelihoods, OCHA said.

The UN Refugee Agency (UNHCR) said that more than 33,300 Iranians reportedly crossed from Turkiye back into Iran and 36,000 people returned to Afghanistan since the start of the war on Feb 28.

OCHA said that Iranian authorities, with support from the IRCS, continue to lead response efforts, including search and rescue, emergency medical care and temporary shelter. The World Food Programme, the UN Children's Fund, UNHCR and the UN Development Programme, along with their humanitarian partners, are supporting food, health, water, education and refugee assistance.

The humanitarian office said that in Lebanon, the country's Ministry of Public Health reported that a total of 1,094 people have been killed and more than 3,000 injured. More than 1 million people have been displaced, while displacement orders continue.

The World Health Organization said there were 77 attacks on healthcare workers in Lebanon, including 53 deaths and 117 injuries. At least 50 primary health care centers and five hospitals have been closed due to hostilities, while nine hospitals and four primary health care centers have sustained damage.

Meanwhile, across the Gaza Strip, suffering heavier aid restrictions since the conflict escalated in the Middle East, heavy rains have damaged displaced people's shelters and belongings since Wednesday.

OCHA said that since Wednesday, at least 120 families have had their tents or other types of shelter flooded, destroyed or damaged.

However, the office said that the relief operations, like most aid work in Gaza, are subject to a range of obstructions, including restrictions on the import of critical items and disruptions to the supply chain.

OCHA said that reports of shelling, gunfire and other attacks continue. On Wednesday, an airstrike destroyed 15 shelters and damaged 30 others in a displacement site in Deir al Balah, raising more concern over the protection of civilians.

"Residential areas should be protected; this includes avoiding placing military objects in or near them -- and respecting the prohibition on indiscriminate attacks," OCHA said.