Israel has continued to strike at what it says are militant targets across the Palestinian enclave even as attention has shifted to its war against Hezbollah in Lebanon and rising tensions with Iran.
It launched a large-scale air and ground operation against Hamas in northern Gaza earlier this week.
The Al-Aqsa Martyrs Hospital, where the bodies were brought on Thursday, confirmed the toll from the strike in the central town of Deir al-Balah.
It said several other people were wounded in the strike.
An Associated Press reporter saw ambulances streaming into the hospital and counted the bodies, many of which arrived in pieces.
There was no immediate comment from the Israeli military.
Witnesses said the strike targeted a makeshift post of the Hamas-run police inside the shelter.
Israel has repeatedly attacked schools-turned-shelters in Gaza, accusing militants of hiding out there.
Hamas has continued to launch attacks on Israeli forces and fire occasional rockets into Israel more than a year after its October 7 attack ignited the war.
Hamas-led militants stormed into Israel and rampaged through army bases and farming communities in that attack, killing some 1200 people, mostly civilians, and abducting about 250 others.
They are still holding about 100 captives, a third of whom are believed to be dead.
Israel's offensive has killed more than 42,000 Palestinians, according to local health authorities, who do not say how many were fighters but say women and children make up more than half of the fatalities.
The war has destroyed large areas of Gaza and displaced around 90 per cent of its population of 2.3 million people, often multiple times.
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