Israel-Gaza updates: US Embassy says American injured by Hezbollah rocket fire

All patients and medical staff have left European Gaza Hospital in southern Gaza, following evacuation orders from the Israel Defense Forces in Khan Younis, the World Health Organization said Tuesday.

The hospital, which had 320 patients, is "now completely empty," WHO Director-General Tedros Adhanom Ghebreyesus said.

"It is devastating to see the 650-bed-capacity hospital out of service at a time when access to health care is urgently needed," he said in a statement while calling on the hospital to be made operational "immediately."

Most patients were being referred to Nasser Medical Complex, which is now at full capacity and facing a shortage of medical supplies, the WHO said.

The Israel Defense Forces' evacuation order for a region in southern Gaza on Monday was the largest such order since October 2023, according to the United Nations.

The United Nations Relief and Works Agency for Palestine Refugees in the Near East estimated that 250,000 people are impacted by the evacuation order in Khan Younis. The evacuation zone covers 117 square kilometers, according to U.N. spokesperson Stephane Dujarric.

"[The United Nations Office for the Coordination of Humanitarian Affairs] underscores that an evacuation of such a massive scale will only heighten the suffering of civilians and drive humanitarian needs even higher," Dujarric said in a statement Tuesday. "People are left with the impossible choice of having to relocate, some most likely for the second or even the third time, to areas that have barely any space or services, or stay in an area where they know the fighting will take place."

The IDF said it ordered Palestinians to evacuate amid its response to a rocket attack that came from the area involving approximately 20 projectiles, some of which fell inside southern Israel.

The Israel Defense Forces ordered hundreds of people in Khan Younis in southern Gaza to evacuate amid its response to a rocket attack, the military said.

The area for evacuation is near the European Hospital, according to a leaflet distributed in the region Monday.

"For your safety, you must evacuate immediately to the humanitarian zone," the leaflet stated.

The IDF said the evacuation is in response to an earlier rocket attack that came from the area involving approximately 20 projectiles.

"A number of the projectiles were intercepted and some of the projectiles fell inside southern Israel. No injuries were reported," the IDF said in a statement. "IDF Artillery is currently striking the sources of the fire."

-ABC News' Sami Zyara and Matt Gutman

Noa Argamani, one of four hostages rescued during a deadly IDF raid on June 8, released a video thanking Israeli forces for rescuing her and calls for the release of the remaining hostages, including her boyfriend, in her first public remarks since she was released.

They were separated during the kidnapping, according to Argamani.

"I want to take this opportunity to remind everyone that there are still 120 hostages in Hamas captivity. Among them is Avinatan Or, my partner, from whom I was separated at the moment of abduction. Although I'm home now, we can't forget about the hostages who are still in Hamas captivity, and we must do everything possible to bring them back home," Argamani said.

-ABC News' Victoria Beaule