The Israeli military said on Tuesday it will act with "greater force" in Gaza City and warned residents, in a statement posted on X, to flee.

"To all residents of Gaza City... the defence forces are determined to defeat Hamas and will act with greater force in the Gaza City area," Colonel Avichay Adraee said in the post.

"Evacuate immediately via the Al-Rashid axis," he added, after Israeli Prime Minister Benjamin Netanyahu warned residents of the Gaza Strip's largest urban centre to leave.

Netanyahu said on Monday that Israel plans to destroy at least 50 “towers of terror” that he said are used by Hamas.

Defense Minister Israel Katz said the country had demolished 30 high-rise buildings in Gaza, which it accused Hamas of using for military infrastructure.

The demolitions are part of Israel's ramping up its offensive to take control of what it portrays as Hamas’ last remaining stronghold, urging Palestinians to flee parts of Gaza City for a designated humanitarian zone in the territory’s south.

There are around one million Palestinians in the area of Gaza City, though prior to this warning just a small fraction have evacuated.

Hamas said Netanyahu's threat amounted to an "explicit act of forced displacement" of Gaza City residents.

"It is taking place under the weight of bombardment, massacres, starvation and threats of death-constituting a blatant and unprecedented challenge to international laws and conventions," it said in a statement.

Gaza civil defence agency said Israeli air strikes continued overnight across Gaza City. (Agencies)