https://bbc.com/news/world-middle-east
The claims were made by South African lawyers as it presented its case accusing Israel of genocide at the International Court of Justice.
South Africa also called on the court to order Israel to cease military operations in Gaza.
Israel - which will present its defence on Friday - has vehemently rejected the accusations as "baseless".
The court will deliver only an opinion on the genocide allegation, although it is being closely watched.
Tembeka Ngcukaitobi, a lawyer for the High Court of South Africa, told the ICJ Israel's "genocidal intent" was evident "from the way in which this military attack is being conducted".
"The intent to destroy Gaza has been nurtured at the highest level of state," he said.
Israel will offer its defence on Friday, but has previously said its actions in the Gaza Strip are justified because it is responding to Hamas's deadly attacks on 7 October.
But speaking in court on Thursday, South Africa's Justice Minister Ronald Lamola said that no attack "can provide justification for or defend breaches of the [Genocide] Convention".
Israel is a signatory to the Genocide Convention of 1948, which defines genocide and commits states to prevent it.
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