An Israeli air attack on a crowded tent camp housing Palestinians displaced by the war in Gaza killed at least 40 people and wounded 60 others, Palestinian officials have said.

The attack early on Tuesday was one of the deadliest strikes yet to hit al-Mawasi, a sprawl of crowded tent camps along the Gaza coast that Israel has designated as a humanitarian zone for hundreds of thousands of civilians to seek shelter.

The Palestinian Civil Defence said first responders had recovered 40 bodies and were still looking for people. It added that entire families were killed in their tents.

Rescuers were shown sifting through the sand and rubble with garden tools and bare hands by the light of mobile phones. Body parts were pulled from the sand, including what appeared to be a human leg.

Nasser Hospital in Khan Younis, one of the three medical facilities to receive casualties, said about two dozen bodies were brought in after the attack.

The Israeli military claimed it struck Hamas forces operating in a command-and-control centre, following which the Palestinian group released a statement denying its fighters were in the area.

Israel’s war on Gaza has caused vast destruction and displaced about 90 percent of the enclave’s population of 2.3 million, often multiple times.

Israeli evacuation orders, which now cover much of the territory, have pushed hundreds of thousands of people into al-Mawasi.

Aid groups have struggled to provide even basic services.

Israel has struck targets there many times despite designating it as a humanitarian zone.