South Africans fighting for Israel in Gaza could face prosecution at home, the government warned Monday, as President Cyril Ramaphosa once again denounced the conflict in the Palestinian territory as "genocide".
The foreign ministry said it was "gravely concerned" by reports that some South African nationals have joined the Israeli Defence Forces (IDF) to fight in Gaza or are considering doing so.
"Such action can potentially contribute to the violation of international law and the commission of further international crimes, thus making them liable for prosecution in South Africa," the ministry said.
It did not specify how many South Africans are thought to have enlisted.
The government has previously said the State Security Agency (SSA) was tracking them down.
South Africans need prior government approval to legally fight in Israel, the ministry said.
Naturalised citizens are at further risk of being stripped of their South African nationality for engaging in a war that the country "does not support or agree with", the foreign ministry added.
The war in Gaza broke out when the strip's Islamist rulers Hamas launched an unprecedented attack in Israel on October 7.
Around 1,140 people, mostly civilians, were killed, according to an AFP tally based on official Israeli figures. Another 250 were abducted.
Gaza's Health Ministry says Israel's military response has killed more than 19,400 people, mostly women and children, while reducing vast areas to rubble.
South Africa has long been a vocal supporter of the Palestinian cause, with the ruling African National Congress (ANC) party often linking it to its own struggle against apartheid.
It has strongly condemned Israel's response to the Hamas attacks and has recalled all its diplomats from the country.
On Monday, Ramaphosa denounced the "genocidal onslaught and slaughter of the people of Palestine" at a press conference with representatives of pro-Palestinian groups in Johannesburg.