Israel has warned all residents of Gaza City to leave immediately in anticipation of a huge ground offensive.

The military's Arabic spokesman told as many as one million Palestinians living in Gaza's biggest urban centre to evacuate southwards. Remaining in the area is extremely dangerous, he said.

On Monday, Israeli Prime Minister Benjamin Netanyahu said air strikes that had destroyed high-rise buildings in Gaza City in recent days were only the beginning of the main, intensive operation to capture what he has described as Hamas's last important stronghold.

Hamas responded to the evacuation order, stating it amounts to a public demonstration of a fully-fledged crime of forced displacement. The UN has cautioned that intensifying offensive actions in an already famine-declared area will plunge civilians into an even deeper catastrophe.

The evacuation order, disseminated via leaflets and social media, was clear: To all residents and those present in Gaza City... for your safety, evacuate immediately. Many residents are faced with logistical and financial challenges in moving, further complicating the situation.

Photographs indicated that while some people fled southward, no sign of a mass exodus was evident, highlighting the plight of those unable to leave amidst ongoing conflict.

Amid worsening humanitarian conditions, the Israeli military insists its operations aim to dismantle Hamas, following a cycle of hostilities that has led to significant casualties. The international community watches closely, as hopes for humanitarian aid and safety dwindle.