Gaza Strip, with nearly 200 people reported killed in the past 24 hours of air strikes and artillery barrages on the shattered enclave.
Israeli warplanes attacking the south of Gaza flattened homes and buried families as they slept, residents said.
The new assaults in central and southern Gaza propelled a new exodus of people already driven from other areas in what Israeli Defence Minister Yoav Gallant called an essential stage of its mission to destroy its foe Hamas.
Twelve weeks after Hamas militants stormed Israeli towns, killing 1,200 people and seizing 240 hostages, Israeli forces have laid much of the Gaza Strip to waste.
Nearly all its 2.3 million people have fled their homes at least once and many are now on the move again, often reduced to taking shelter in makeshift tents or huddled under tarpaulins and plastic sheets on open ground.
Gaza health authorities said 187 more Palestinians were confirmed killed in Israeli strikes in the past 24 hours, raising the toll to 21,507 — about 1% of Gaza's population. Thousands more bodies are feared to be buried in the ruins of obliterated neighbourhoods.
In Rafa in the south, Reuters journalists at the scene of one air strike that destroyed a building saw the head of a buried toddler sticking out of the rubble.
The child screamed as a rescue worker shielded his head with a hand, while another swung a sledgehammer at a chisel, trying to break up a slab of concrete to free him.
Neighbour Sanad Abu Tabet said the two-storey house had been crowded with displaced people. After morning broke, relatives came to collect the dead wrapped up in white shrouds. A man peeled away the cloth to stroke the face of a dead