Israeli military tanks have ventured into the camp after five Israeli soldiers were killed over the weekend.
ADVERTISEMENTLocal media reported that Israeli military tanks entered Jabalia refugee camp overnight after the IDF warned that 100,000-150,000 Palestinian civilians would need to "evacuate".
The Jabalia refugee camp is densely populated, and local media reported military tanks were surrounding evacuation centres and residential buildings.
Mustafa Barghouti, who is the head of the Palestinian National Initiative party, posted a video claiming to show Israel's bombardment of the camp.
The video cannot be independently verified.
Gaza civil defence has said its teams are unable to access the camp since Israel ordered fresh bombings on Sunday, Turkey's Anadolu news agency reported.
Israeli military spokesman Daniel Hagari said that in addition to Jabalia Israeli forces are also operating in Beit Lahiya and Beit Hanoun.
It comes as Israel launched strikes across Gaza after it expanded an evacuation order in the strip's southern Rafah.
UN Secretary-General Antonio Guterres urged an immediate halt to the war on Gaza, the return of hostages and a "surge" in humanitarian aid to the besieged Palestinian territory.