Just two days after taking out a loan to set up a makeshift home in a tent encampment for his family, Mohammed Kark felt water at his feet as the family was sleeping Sunday night.

"All of a sudden I saw the ocean attacking me and my kids and people screaming," he told CBC News on Monday. 

Kark, who is on crutches due to a leg injury, said others rushed to help rescue his two children — ages six and seven — from the water that was sweeping away some of the seaside tent encampments in Khan Younis in southern Gaza.

"We got soaked, us and our neighbours," he said.  

"They took my wife and kids … I had to find our things underwater."

Kark's family was one of hundreds of families whose tents — made of plastic and cloth — were flooded and swept away by the heavy rains and rising sea levels in Khan Younis on Monday, according to eyewitnesses who spoke with CBC News. Most of the families have already been uprooted several times in the 13-month-long war between Israel and Hamas.

For many displaced Palestinians, winter conditions are destroying the few remaining items they have after more than a year of ongoing bombardment and lack of basic items, including food, clothes and medical supplies.

'God saved us but we lost everything'

Mohammed Al-Najjar said he was released from an Israeli prison on Saturday and came to seek shelter at the beach encampment with his wife, uncle and one-year-old son. 

The 25-year-old said his son was swept by the sea along with the family's belongings.

"He was so wet and sick," Al-Najjar said about his son, whom he took to get checked by a pharmacist. 

"The water took all our things. The pots and plates, everything went into the ocean. There's nothing left. The [tents] were destroyed, all our wood is gone," he told CBC News.

"God saved us but we lost everything."

Mariam Abu Saqer said her daughter was also swept away by the sea.

"Thank God we were able to rescue her," she told Reuters.

"Where should we go? Wherever we go, they tell us there is no space."

Thousands affected by seasonal flooding

Abu Ahmed Al-Arqan said he helped get women out of the affected tents all night.

"The water came in on us while we were sleeping. What can we do?" Al-Arqan said.

"We're dying … they're slaughtering us," he told CBC News, referring to ongoing bombardments that Israel says are aimed at stopping Hamas fighters from waging more attacks and regrouping across the Gaza Strip.

The Palestinian Civil Emergency Service said on Monday that thousands of displaced people were affected by seasonal flooding and called for new tents and caravans from aid donors to protect them.

Many tents used early in the war have now worn out and no longer offer protection, but the price of new tents and plastic sheeting has shot up beyond the means of displaced families.

Some families at the tent encampment told CBC News they sought shelter near the beach because of overcrowding in other areas in Khan Younis.

The UN Palestinian refugee agency UNRWA says around half a million displaced Palestinians are at risk in areas of flooding, with the first rains of winter meaning even more suffering.

"The situation will only get worse with every drop of rain, every bomb, every strike," it said in a post on X Monday.

WATCH | Heavy rains flood tent camps earlier in September:

Heavy rains flood tent camps of displaced Palestinians in Gaza

A tent camp for displaced Palestinians flooded Sunday after heavy rains caused pooling in Khan Younis, in the southern Gaza Strip. The downpour continued to fall Monday, flooding more tents across Gaza, washing some away and forcing families out of their sleep.

'Desperate situation must end,' UNRWA says

UNRWA said families in Gaza City are entering winter in appalling conditions with nowhere safe to shelter.

"Rain is pouring down and they need everything, including clothes, shoes, blankets and mattresses, as the cold is settling in," it said in another post. "This desperate situation must end."

In another part of Khan Younis, rainwater entered a school housing displaced families. Suad Al-Sabea, a mother of six from northern Gaza who lives inside a classroom with broken windows at the school, said the rain that seeped in spoiled the flour and damaged a wood-fuelled earth oven that she uses to sell bread to make a living.

"I was scared of life or death; now we worry about the rain," she said.

"The dough drowned in water, and many mattresses drowned in water. It was raining on top of my head and I kept baking to provide for my children," Al-Sabea told Reuters on Monday.

WATCH | Mosque in central Gaza hit by strike over the weekend: 

Footage shows strike on mosque in central Gaza

Video obtained by CBC News and Reuters shows the moment a mosque in Nuseirat, Gaza, was hit by an airstrike. Witnesses say they were told to evacuate the area by the Israel Defence Forces before the strike.

Meanwhile, Israeli military strikes intensified across the war-torn enclave Monday. In Rafah in southern Gaza, an Israeli airstrike killed at least four people, medics said, while tanks deepened their incursions in the northern edge of two towns of Beit Hanoun, and in Beit Lahiya, and Jabalia, the largest of the enclave's eight historic refugee camps.

Medics said seven Palestinians were killed by two Israeli airstrikes in the area of Jabalia.

Israel's campaign in Gaza has killed more than 44,200 people, and uprooted nearly the entire population at least once, according to Gaza officials, while reducing wide swathes of the narrow coastal territory to rubble.

The war erupted in response to a cross-border attack by Hamas-led militants on Oct. 7, 2023 in which gunmen killed around 1,200 people and took more than 250 hostages back to Gaza, according to Israeli tallies.