Thousands of reservists have begun reporting for duty as the Israeli military presses ahead with its offensive to conquer Gaza City.
Ground forces are already pushing into the outskirts of Gaza's largest urban area, which the military has said is a stronghold of Hamas.
The city is also coming under heavy Israeli aerial and artillery bombardment, with local hospitals saying that more than 50 Palestinians have been killed there since midnight.
The military has ordered residents to evacuate and head south immediately. The UN says an estimated 20,000 have done so over the past two weeks, but almost a million remain.
UN humanitarian officials have warned that the impact of a full-blown offensive would be beyond catastrophic, not only for those in the city but for the entire Gaza Strip.
Last month, the Israel Defense Forces (IDF) said about 60,000 reservists would be called up ahead of Operation Gideon's Chariots II – the next phase of the ground offensive that it launched in May and has seen it take control of at least 75% of Gaza.
On Tuesday, an Israeli military official said thousands had begun reporting for duty.
Israeli media said many of the reservists would be deployed to the occupied West Bank and northern Israel to free up active-duty personnel for the offensive.
Prime Minister Benjamin Netanyahu announced that Israel would conquer all of Gaza after indirect talks with Hamas broke down in July.
At a government meeting, he stated that the IDF's objectives were defeating Hamas and releasing all of our hostages.
As the military offensive escalates, families of hostages urge the government to negotiate their release, fearing for their loved ones' safety amidst increasing violence.
The situation has grown dire, with hospitals in Gaza overwhelmed with casualties from Israeli strikes, exacerbating a looming humanitarian crisis in the region.
