The bodies arrived through the night at the morgue of a hospital in Deir al-Balah in the centre of the Gaza Strip.
By Monday morning, hospital director Iyad al-Jabri had counted 58 dead, saying "dozens of women and children" may still be buried under the rubble.
Overnight, the skies over the Palestinian coastal territory were streaked with flashes of yellow and plumes of red.
It came as the Israeli army said its land assault on Gaza had split the narrow territory in two and warned of "significant" strikes as part of its campaign to destroy Hamas in response to the militants' unprecedented 7 October attacks.
Since Hamas unleashed the attacks, around 1,400 people, mainly civilians, have been killed in Israel and more than 240 have been taken hostage, according to Israeli officials.
In Gaza, more than 10,000 people have been killed in Israeli strikes, most of them women and children, the health ministry in the Hamas-run territory said in an updated toll issued on Monday.
At least 292 Palestinians were killed overnight from Sunday into Monday in intense Israeli army bombardments, Gaza's Hamas-controlled health ministry said Monday.
On the ground in Gaza, Mohammed Meshmesh, 54, said he had lost several members of his family in the Israeli strikes.
"It's a ferocious campaign," Meshmesh told AFP. "The strikes have increased and the victims are women and children, just civilians."
"We weren't expecting this. Communications were cut," he said.
On Sunday night, for the third time since the start of the war between Israel and Hamas, Gaza's 2.4 million inhabitants spent the night cut off from the outside world and with no way to contact their friends and relatives.
Meshmesh, who recently left the Nuseirat refugee camp in central Gaza, said he only heard about the death of his relatives at dawn.
When the bombs were falling on the neighbourhood of Al-Mashaala in Deir al-Balah, his cousin Mahmud Radwan Meshmesh likewise was unable to call an ambulance.
"We had to send someone in a car to take the first dead to the morgue, and tell the ambulances so that they could come get the bodies," the 47-year-old said.
"These are massacres! They destroyed three houses on top of the residents, women and children.
"There were more than 60 people in these homes and we have already pulled out 40 bodies from the debris."
When the bombs fell on the buildings, "it was like an earthquake... an absolutely enormous explosion", he said.
Mohammed Abu Laila thought he would be away from harm in the centre of the Gaza Strip.
The 34-year-old Palestinian left with his family from their home in Al-Saftawi after the Israeli army called on 1.1 million Gazans in the north to move south as it began its offensive.
But around 11:00 pm on Sunday, in the Nuseirat refugee camp where he had set up, "we felt a strike and we found ourselves under the rubble", Laila said.
"We were 120 people in the house. Many were killed or injured," he said.
"We have already said the prayer for the dead for around 50 people."