Medics said families displaced by the 14-month-old conflict had sought refuge in the postal facility in Nuseirat camp. The attack late on Thursday damaged several houses nearby.
Israel said it was targeting a senior Islamic Jihad member when it hit the structure.
Prime Minister Netayahu's Message to the Iranian People:— Prime Minister of Israel (@IsraeliPM) "Your oppressors spent over 30 billion dollars supporting Assad in Syria. After only 11 days of fighting, his regime collapsed into dust." pic.twitter.com/njhjXyHmmFDecember 12, 2024
Some of the bodies gathered on Friday al Al-Awda Hospital in Nuseirat were wrapped in white shrouds and others in blankets from home. The families accompanied them on a walk to their graves.
"They have killed the hope and optimism," said Suheil Mattar, whose grandchildren and daughter-in-law were killed.
"Every time things happen and we say there will be a truce and we will rest ... After that, they change their minds, they change their minds. We don't know why," Mattar said.
Months of ceasefire efforts by Arab mediators Egypt and Qatar, backed by the United States, have failed to conclude a deal between the two warring sides.
Israel said it had targeted an Islamic Jihad leader of attacks on Israeli civilians and troops. It accused the militant group of exploiting civilian infrastructure and the population as a human shield for its activities. It did not identify the Islamic Jihad member by name.
Nuseirat is one of the Gaza Strip's eight historic camps originally for Palestinian refugees from the 1948 war around the establishment of Israel. Today, it is part of a dense urban area crowded with displaced people from throughout the enclave.
"We've seen absolutely horrific images from the scene," Louise Wateridge, a senior emergency officer for the UN Palestinian relief agency, told a UN press briefing in Geneva on Friday.
"There are parents looking for their children, children covered in dust and blood, looking for their parents, multiple injuries on top of the casualties reported and people still buried under the rubble."
On Friday, Palestinian health officials said at least 12 people were killed in separate Israeli airstrikes across the enclave, including three in a tent housing a displaced family in Khan Younis and a local journalist in Gaza City.
Relatives of hostages held by Hamas protest outside the US Embassy in Tel Aviv, Israel. (AP PHOTO)
US national security adviser Jake Sullivan said in Tel Aviv on Thursday he believed a deal on a Gaza ceasefire and hostage release may be close as Israel had signalled it was ready and there were signs of movement from Hamas.
The war in the Palestinian enclave began after Hamas gunmen on October 7, 2023, stormed into Israel, killing around 1200 people and taking about 250 hostages back to Hamas-run Gaza, according to Israeli tallies. Some 100 hostages remain in Gaza.
Since then, Israel's military has levelled swathes of Gaza, driving nearly all of its 2.3 million people from their homes, giving rise to deadly hunger and disease and killing nearly 44,900 people, according to Palestinian health authorities.
