The shocking death toll for Tuesday alone comes as Israel keeps pounding the besieged Palestinian enclave for the 22nd consecutive day.
Israeli warplanes carried out at least 60 air strikes, targeting residential areas and civilian sites across the impoverished region.
Israeli army pounded several areas including Gaza city, Khan Yunis and Rafah over the past few hours. Several UN staff members are said to be among those killed in the ongoing Israeli air and ground attacks.
Palestinian officials say this has been the bloodiest day in the Gaza Strip in recent years.
The number of Palestinian civilian casualties has dramatically increased since Israeli Prime Minister Benjamin Netanyahu threatened to escalate the war on Gaza Monday night.
Palestinian officials say at least 55 houses were destroyed in overnight bombing, with people buried under rubble.
"Our children... can't hear because of the loud explosions and they are shaking," media outlets quoted Palestinian families as saying.
The overall death toll among the Palestinians has now reached around 1,200. Over 6,700 others have also been injured in the ongoing assault on Gaza.
International bodies and human rights groups say civilians account for the majority of the victims of the ongoing Israeli war. Women and children make the bulk of the civilian casualties there.
Anti-Israel rallies are being held worldwide in condemnation of Tel Aviv's atrocities against Palestinians. The ralliers urge an immediate end to the bloodshed in Gaza.
The protesters burned Israel's flags and called for an end to its aggression on Gaza. They also demanded the boycott of Israeli-made products.