Israeli troops ordered the evacuation of Al-Shifa hospital "in the next hour" over loudspeakers on Saturday, an AFP journalist at the scene reported, as troops combed the facility for Hamas hideouts.

Al-Shifa hospital -- Gaza's biggest -- has become the focus of the Israel-Hamas war, now entering its seventh week after the October 7 attacks on southern Israel.

Israel claims Hamas operates a base underneath Al-Shifa, a charge the militants deny.

The United Nations estimated 2,300 patients, staff and displaced Palestinians were sheltering at Al-Shifa before Israeli troops moved in on Wednesday.

The Hamas health ministry in Gaza has announced dozens of deaths there as a result of power cuts caused by fuel shortages amid intense combat.

Israel has made repeated calls for the hospital to be evacuated to the south, however medical professionals say the patients cannot be moved.

Hospital director Mohammed Abu Salmiya told AFP Israeli troops instructed him to ensure "the evacuation of patients, wounded, the displaced and medical staff, and that they should move on foot towards the seafront".