On Monday, Egyptian authorities allowed ambulances carrying several wounded Palestinians to cross into Egypt through the Rafah border crossing for medical treatment.
Hospitals in Gaza have been overwhelmed by casualties since Israel started its aerial blitz on the territory.
Egypt also allowed lorries loaded with humanitarian aid to enter its border crossing with the Gaza Strip. Lorries with food and medical supplies have been lining up outside the Egypt-Gaza border since early morning.
The UN relief and works agency said on Monday that at least 51 Palestinian civilians, including women and children, were confirmed to be among those killed in the Gaza Strip.