Israel's military ordered the evacuation Saturday of a crowded part of Gaza designated as a humanitarian zone, saying it is planning an operation against Hamas militants in Khan Younis, including parts of Muwasi, a makeshift tent camp where thousands are seeking refuge.

The order comes in response to rocket fire that Israel says originates from the area. It's the second evacuation issued in a week in an area designated for Palestinians fleeing other parts of Gaza. Many Palestinians have been uprooted multiple times in search of safety during Israel's punishing air and ground campaign.

On Monday, after the evacuation order, multiple Israeli airstrikes hit around Khan Younis, killing at least 70 people, according to Gaza's Health Ministry, citing figures from Nasser Hospital.

The area is part of a 60-square-kilometer (roughly 20-square-mile) “humanitarian zone” to which Israel has been telling Palestinians to flee to throughout the war. Much of the area is blanketed with tent camps that lack sanitation and medical facilities and have limited access to aid, United Nations and humanitarian groups say. About 1.8 million Palestinians are sheltering there, according to Israel's estimates. That's more than half Gaza's pre-war population of 2.3 million.

The war in Gaza has killed more than 39,100 Palestinians, according to the territory's Health Ministry, which doesn't distinguish between combatants and civilians in its count. The U.N. estimated in February that some 17,000 children in the territory are now unaccompanied, and the number is likely to have grown since.

The war began with an assault by Hamas militants on southern Israel on Oct. 7 that killed 1,200 people, most of them civilians, and took about 250 hostages. About 115 are still in Gaza, about a third of them believed to be dead, according to Israeli authorities.