Plumes of smoke rose from the southern Rimal neighborhood as the multi-story building collapsed, an Anadolu reporter said.
The tower had sheltered hundreds of displaced Palestinian families, with additional tents for other uprooted civilians surrounding it.
The military ordered residents to evacuate to the al-Mawasi area in southern Gaza, described by Israel as a “safe zone.”
Al-Mawasi has itself faced repeated Israeli attacks that killed and injured hundreds amid worsening humanitarian conditions.
Israel has struck dozens of high-rise towers and hundreds of residential buildings across Gaza City in recent weeks.
Palestinian officials and human rights groups say the pattern is intended to force residents out and clear the city for occupation.
Since October 2023, Israeli assaults have killed more than 66,000 people in Gaza, most of them women and children, leaving the enclave in ruins and triggering starvation and disease.