Intense fighting has blocked relief workers from distributing food, water and medicine across most of the Gaza Strip.
This, authorities say, is deepening the humanitarian crisis as Israeli forces battled Hamas militants on Wednesday in a ground offensive that has brought some of the devastation and mass displacement seen in the north to the south.
As the focus of the offensive moves down the Gaza Strip and into the second-largest city of Khan Younis, it is further shrinking the area where Palestinians can seek safety and pushing large numbers of people, to the sealed-off border with Egypt.
On the Gaza side of the border, makeshift shelters and family homes are already overflowing and many people are sleeping in the streets.
On the other side, Egypt has refused any mass influx of refugees, saying it believes Israel will not let them back into Gaza and that the decades-old peace treaty between the two countries would be undermined.