Israel lashed out Friday at South Africa's case before the UN's top court, describing it as "totally divorced" from reality, as Pretoria urges judges to order a ceasefire in Gaza.
A top lawyer for Israel painted the South Africa case as a "mockery" of the UN Genocide Convention it is accused of breaching.
"South Africa presents the court for the fourth time with a picture that is completely divorced from the facts and circumstances," Gilad Noam told the International Court of Justice (ICJ).
Pretoria has petitioned the ICJ to order a stop to the Israeli assault on the Gaza city of Rafah, which Israel says is key to eliminating Hamas militants.
Israel prime minister Benjamin Netanyahu said Thursday the ground assault on Rafah was a "critical" part of the army's mission to destroy Hamas and prevent a repetition of the 7-October attack.
"The battle in Rafah is critical... It's not just the rest of their battalions, it's also like an oxygen line for them for escape and resupply," he said.
Netanyahu ordered the Rafah offensive in defiance of US warnings that more than a million civilians sheltering there could be caught in the crossfire.
Friday in the Hague, Noam told the court Israel was "acutely aware" of civilians concentrated in Rafah.
"It is also acutely aware of Hamas efforts to use these civilians as a shield," he said.
Noam said there had been no "large-scale" assault on Rafah but "specific and localised operations prefaced with evacuation efforts and support for humanitarian activities."
A few dozen protesters rallied in support of Israel outside the Peace Palace seat of the ICJ, showing pictures of some of the hostages held by Hamas.
And the sitting was briefly interrupted as Israel was concluding its statement, with a woman heard shouting "liars" in the court.
On Thursday, lawyers representing Pretoria presented judges a litany of allegations against Israel, including mass graves, torture and deliberate withholding of humanitarian aid.
"South Africa had hoped, when we last appeared before this court, to halt this genocidal process to preserve Palestine and its people," said top lawyer Vusimuzi Madonsela.
"Instead, Israel's genocide has continued apace and has just reached a new and horrific stage," added Madonsela.
But Noam said that South Africa's accusations made a "mockery of the heinous charge of genocide."
"Calling something a genocide again and again does not make it genocide. Repeating a lie does not make it true," he said.
"There is a tragic war going on but there is no genocide."
It is the fourth time South Africa has appealed to the court, with Israel accusing them of abusing the procedure.
"If anyone should be told enough is enough, it should be South Africa, not Israel," said Noam.
"At what point do we say 'enough' to South Africa's repeated attempts to exploit the provisional measure procedure of this court in such a vile and cynical manner?"
In a ruling that made headlines worldwide, the ICJ in January ordered Israel to do everything in its power to prevent genocidal acts and enable humanitarian aid to Gaza.
But the court stopped short of ordering a ceasefire and South Africa's argument is that the situation on the ground -- notably the operation in the crowded city of Rafah -- requires fresh ICJ action.
The orders of the ICJ, which rules in disputes between states, are legally binding but it has little means to enforce them.
It has ordered Russia to halt its invasion of Ukraine, to no avail.
South Africa wants the ICJ to issue three emergency orders -- "provisional measures" in court jargon -- while it rules on the wider accusation that Israel is breaking the 1948 UN Genocide Convention.
It wants the court to order Israel to "immediately" cease all military operations in Gaza, including in Rafah, enable humanitarian access and report back on its progress on achieving these orders.
The Hamas attack on 7 October resulted in the death of more than 1,170 people in Israel, most of them civilians, according to an AFP tally based on official Israeli figures.
Out of 252 people taken hostage that day, 128 are still being held inside the Gaza Strip, including 38 who the army says are dead.
At least 35,303 Palestinians, mostly civilians, have been killed in the Gaza Strip since the war broke out, according to data provided by the health ministry of Hamas-run Gaza.
Israeli military says 279 soldiers have been killed in the Gaza military campaign since the start of the ground offensive on 27 October