Thousands broke into the warehouses of the U.N. Relief and Works Agency in the Gaza Strip, taking wheat flour and basic items, according to the aid agency.
Thomas White, director of UNRWA affairs in Gaza said it was "a worrying sign that civil order is starting to break down."
Meanwhile, Israel pledged to continue its "large scale, significant strikes" in pursuit of Hamas militants responsible for the Oct. 7 carnage.
"Overnight, IDF forces entered the northern Gaza Strip and expanded ground activities," Israel Defense Forces spokesperson, Rear Admiral Daniel Hagari, said. "The expansion of the IDF's operational activity furthers the war's goals."
It comes as Israel enters the second phase of its war against Hamas, which Prime Minister Benjamin Netanyahu said will be "long and difficult."
Palestinian leader Mahmoud Abbas has called on the international community to stop Israel's attacks on Gaza, and said people trapped in the Palestinian enclave are "facing a war of genocide" even as the world watches on.
Meanwhile, the IDF reiterated calls for citizens in Gaza to move south in a renewed warning. "Today, we increase the urgency of that warning," Hagari said in a video posted on social media, highlighting that residents have been told to leave for two weeks now.
Since the start of the war, more than 7,700 people in Gaza have been killed — nearly half of them children, according to the Gaza health ministry which is controlled by Hamas. In Israel, at least 1,400 people were killed and 229 people are believed to have been kidnapped into Gaza.