The Civil Defense in Gaza said in a statement that Israeli attacks since dawn on Saturday had killed 37 people, including women and children.
Separately, Palestinian medical sources said the death toll had reached 37 after a series of intense Israeli raids on multiple areas of the enclave.
Meanwhile, field sources said Israeli aircraft struck the Sheikh Radwan police station in western Gaza City, killing several police officers, staff members and civilians who were inside or nearby at the time of the attack.
They said some of those killed were people seeking assistance or dealing with legal matters at the station, while rescue and civil defense teams continued searching for missing individuals beneath the rubble.
In a related development, the strikes extended to the al-Nasr neighborhood in western Gaza City, where residents said Israeli attacks hit inhabited homes and areas near UNRWA schools, causing further deaths and injuries.
Medical officials said hospitals were receiving a steady flow of casualties as the bombardment continued.
Israeli aircraft also hit a house belonging to the Rizq family near the Da’our Tower in the Nasr neighborhood, and struck areas near what residents described as the intelligence zone north of Gaza City, triggering panic and displacement.
According to hospital data, most of the fatalities were reported in northern Gaza, with 25 deaths recorded there, compared with seven deaths in the southern part of the territory.
Medical teams said continued shelling and access constraints had prevented them from reaching all affected locations.
Commenting on the escalation, Hamas spokesman Hazem Qassem said Israel was seeking through the attacks to send a message that "empties all political efforts and attempts to establish a ceasefire of their content."
He described the situation as a continuing war of extermination against the Palestinian people.
In a separate warning, the head of the NGO network in Gaza said daily bombardment was driving ongoing displacement, adding that the territory was entering what he called a very dangerous phase.
He said this was due to Israel blocking the entry of aid and essential supplies and targeting law enforcement institutions.
The Ministry of Interior and National Security also condemned the strike on the Sheikh Radwan police station, calling it a massacre and a violation of the ceasefire agreement.
The ministry said targeting police and civilian facilities was part of what it described as a policy of "engineering chaos."
By contrast, Israeli military sources said the strikes were carried out in response to a "violation of the ceasefire agreement."
Palestinians rejected that claim, saying it was used to justify continued attacks on civilians.
As rescue operations continued, medical sources warned that the death toll could rise in the coming hours due to people still missing under the rubble and ongoing strikes on densely populated areas.
They said the latest attacks marked another day of heavy civilian casualties in the Gaza Strip.