The head of the top United Nations court on Friday began reading the initial decision in the case against Israel over alleged genocide in Gaza, a landmark case that has sparked global interest.

The International Court of Justice (ICJ) could in theory order Israel to stop its military campaign in Gaza, sparked by the October 7 attacks by Hamas, or to facilitate humanitarian aid.

The court is not however passing judgement on whether or not Israel is actually committing genocide in Gaza.

At this stage, the ICJ is weighing emergency orders while it considers the wider accusation of genocidal acts in Gaza -- a process likely to take years.

South Africa has brought the case, accusing Israel of breaching the 1948 UN Genocide Convention, set up in the ashes of World War II and the Holocaust.

Pretoria "does not need to prove that Israel is committing genocide," said Juliette McIntyre, international law expert from the University of South Australia.

"They simply need to establish that there is a plausible risk of genocide occurring," she told AFP.

Over two days of hearings earlier this month in the gilded halls of the Peace Palace in The Hague, a world away from the violence in Israel and Gaza, robed lawyers battled over the technicalities of the Genocide Convention.

"Genocides are never declared in advance," declared Adila Hassim, a top lawyer for South Africa.

"But this court has the benefit of the past 13 weeks of evidence that shows incontrovertibly a pattern of conduct and related intention that justifies a plausible claim of genocidal acts," she added.

Ahead of Friday's ruling, Foreign Minister Naledi Pandor said South Africa was "hopeful" and that the "very important achievement" was to highlight what she called "the plight of the innocent in Palestine".

From Gaza's southern city of Rafah, Mohammed Rabia, 36, who has been displaced from the Al-Shati refugee camp, said he hoped the ICJ would "stand by us and do us justice in the world."

"I hope that the court will decide to condemn Israel, stop the war and (allow us) to go back to our homes," he told AFP.

- 'World is upside down' -

The case has sparked fury in Israel, with Prime Minister Benjamin Netanyahu declaring that "the world is upside down".

Israel's lawyer Tal Becker dismissed Pretoria's case as a "profoundly distorted factual and legal picture" and a "decontextualised and manipulative description of the reality" on the ground.

Showing the court images of the Hamas attack, Becker said: "If there have been acts that may be characterised as genocidal, then they have been perpetrated against Israel."

Becker denied Israel's operations were aimed at the citizens of Gaza.

The army's aim was "not to destroy a people but to protect a people, its people, who are under attack on multiple fronts", he said.

The ICJ's rulings are binding on all parties but it has no mechanism to enforce them.

Sometimes they are completely ignored -- the court has ordered Russia to stop its invasion of Ukraine for example.

Netanyahu has already suggested he does not feel bound by the court, saying: "No-one will stop us -- not The Hague, not the Axis of Evil and no-one else".

Hamas said on the eve of the ruling that it would abide by a ceasefire order if Israel did the same.

- 'Huge' symbolic impact -

"It is conceivable that an order by the court would not have any significant influence on Israel's military operation," said Cecily Rose, assistant professor of public international law at Leiden University.

But if the court decides there is a risk of genocide in Gaza, it could still have a ripple effect, notably on other nations that back Israel politically or militarily.

"It makes it much harder for other states to continue to support Israel in the face of a neutral third party finding there is a risk of genocide," said McIntyre.

"States may withdraw military or other support for Israel in order to avoid this," she added.

In addition, she noted the "huge" symbolic impact of any ruling against Israel under the Genocide Convention, given its tragic history.

In its submission to the court, South Africa acknowledged the "particular weight of responsibility" of accusing Israel of genocide but said it was bound to uphold its duties under the Convention.

Israeli lawyer Becker retorted: "There can hardly be a charge more false and more malevolent than the allegation against Israel of genocide."

The October 7 Hamas attack resulted in the death of around 1,140 people in Israel, most of them civilians, according to an AFP tally based on official Israeli figures.

At least 26,083 Palestinians -- around 70 percent of them women, young children and adolescents -- have been killed in the Gaza Strip in Israeli bombardments and ground offensive since then, according to the Hamas government's health ministry.