Health authorities in Gaza say four months of fighting between the Israeli military and Islamic group Hamas has resulted in more than 27,500 deaths.
The clashes began on October 7 when Hamas launched a surprise attack against Israel.
In early days of the conflict, the Israeli military told residents in northern areas to flee to south, and attacked Gaza City where it claimed Hamas had strongholds.
The UN agency for Palestinian refugees, or UNRWA, on Monday released a video that shows a destroyed health center and its surroundings in northern Gaza.
The agency said, "This is an unprecedented level of destruction and forced displacement, taking place in front of our eyes."
The Israeli military has shifted its focus to southern areas. It said on Tuesday that "dozens of terrorists have been killed" in fighting in Khan Younis.
Health officials in Gaza said on Tuesday that 107 people died during the past 24-hour period.
Israel has indicated that it will continue ground offensives in Rafah, where it believes the last Hamas stronghold is located.
Concerns for further civilian casualties are growing, as more than one million people have been evacuated to the territory's southernmost city.
Meanwhile, Hamas still holds 136 Israelis and foreign nationals hostage.
Negotiations for halting fighting and securing the release of the hostages have been ongoing under the mediation of Qatar and Egypt.
It remains unknown whether a deal can be reached, because Israel is rejecting Hamas's request for a complete ceasefire.