Describing what is happening in the north of the strip today as "the darkest moment of the Gaza conflict," Volker Turk called on the world leaders to act in a statement.
"The bombing in North Gaza is non-stop," he said. "The Israeli military has ordered hundreds of thousands to move, with no guarantees of return. But there is no safe way to leave: the bombs continue to fall; the Israeli military is separating families and detaining many people; and people fleeing have been reportedly shot at."
"Unimaginably, the situation is getting worse by the day. The Israeli Government’s policies and practices in northern Gaza risk emptying the area of all Palestinians," he said, and warned: "We are facing what could amount to atrocity crimes, including potentially extending to crimes against humanity."
Stressing that there is "extremely limited" access to the north of Gaza, the high commissioner said: "Next to no aid has reached the area in weeks, with unlawful restrictions remaining, and many are now facing starvation."
He noted that already over 150,000 people are reportedly dead, wounded, or missing in Gaza.
"My gravest fear is, given the intensity, breadth, scale, and blatant nature of the Israeli operation currently underway in North Gaza, that number will rise dramatically," he added.
Turk said that states have a duty under the Geneva Conventions to ensure respect for international humanitarian law.
"To all the world’s leaders, I remind you of your responsibility to ensure respect for international humanitarian law as set out in the Geneva Conventions. These are universally accepted and binding norms developed to preserve the very bare minimum of humanity," he said, and added: "I implore you to put the protection of civilians and human rights first, and not to abandon that minimum of humanity."
Israel has continued a devastating offensive on Gaza since an attack in October of last year by the Palestinian resistance group Hamas, despite a UN Security Council resolution demanding an immediate cease-fire.
More than 42,800 people have since been killed, mostly women and children, and over 100,500 others injured, according to local health authorities.
The Israeli onslaught has displaced almost the territory’s entire population amid an ongoing blockade that has led to severe shortages of food, clean water, and medicine.
Israel faces a genocide case at the International Court of Justice for its actions in Gaza.