It comes after Israel ordered residents of several towns and villages surrounding Khan Younis and Rafah to evacuate the day before.

"An evacuation of such a massive scale will only heighten the suffering of civilians and drive humanitarian needs even higher."

United Nations spokesman Stephane Dujarric said it was the largest evacuation order in the Strip since 1.1 million people were told to leave the north of the enclave in October, citing figures from the U.N. Palestinian refugee agency UNRWA.

Also read: Israel war on Gaza has displaced 1.9 million Palestinians, UN reports

“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."

Thousands who had not heeded evacuation orders were forced to flee their homes overnight during the Israeli bombardment.

Gaza’s European Hospital in Khan Younis, which the emergency department director says has provided continuous daily services since the beginning of the war, was forced to evacuate.

Also read: Palestinian militants fire rockets into Israel, tanks advance in Gaza

This man whose sick daughter was being treated there says it was their last resort as many hospitals have been destroyed. “Whoever gets wounded, will die,” he says.

Israel s leaders have said they were winding down the phase of intense fighting against Hamas, the Islamist group that has governed Gaza since 2007, and would soon shift to more targeted operations.

The war in Gaza began when Hamas burst into southern Israel on Oct. 7, killed 1,200 people and took around 250 hostages, according to Israeli tallies.

The offensive launched by Israel in retaliation has killed nearly 38,000 people, according to the Gaza health ministry, and has left the coastal enclave in ruins.