Palestinian health officials said Israeli strikes across Gaza killed at least 19 Palestinians from the morning of 2 August.
They described the toll as the highest reported in a single day in recent weeks.
Medical staff at Al-Shifa Hospital said three members of a family, including a pregnant woman and a five-year-old child, were killed in a strike on an apartment at Al-Susi Tower in western Gaza City.
In al-Qarara, northwest of Khan Younis, three members of another family were killed in a strike on an apartment.
Doctors at Nasser Hospital said three other people were injured in the al-Qarara attack.
In Deir al-Balah, a couple were killed at their home and two brothers were killed while travelling by motorcycle.
The accounts also reported one death in Jabalia refugee camp, one in al-Mawasi, two in a drone strike in Gaza City’s Rimal area, and four in a strike on a vehicle in Gaza City.
Those location-by-location accounts enumerate 18 deaths, leaving one death in the stated overall toll without a specified location.
Gaza’s Health Ministry said a strike on 1 August destroyed two medicine-storage facilities at Al-Aqsa Martyrs Hospital in Deir al-Balah and severely damaged two more.
Munir al-Bursh, the ministry’s director general, said the destruction of medical supplies was turning medicine and illness into instruments of war.
Doron Spielman, a spokesman for the Israeli prime minister’s office, said Israeli forces would not withdraw unless Hamas completely disarmed.
Israeli Energy Minister Eli Cohen said there was no obligation to halt attacks during negotiations.
Hamas alleged that Israel was escalating attacks to undermine an understanding with the United States; the allegation could not be independently assessed from the evidence provided.
Nikolay Mladenov, described as the Board of Peace’s chief envoy, said mediators were continuing efforts to calm the situation.