Dozens of people took to the streets in Cape Town on Thursday in one of several demonstrations planned across South Africa in support of the government's genocide case against Israel.
Lawyers for Pretoria are presenting their case at the UN's top court in The Hague, where South Africa lodged an urgent appeal to force Israel to "immediately suspend" its military operations in Gaza.
Standing on the steps of the High Court in the southwestern port city of Cape Town, pro-Palestinian demonstrators held signs reading "Stop the genocide" and "Boycott apartheid Israel". "Free Palestine," some chanted.
Further rallies are planned in Cape Town and other cities.
Robed officials from South Africa and Israel are going head-to-head before the International Court of Justice (ICJ) in the Netherlands.
South Africa argues that Israel is breaking its commitments under the UN Genocide Convention, alleging the bombing and invasion of Gaza is "intended to bring about the destruction of a substantial part of the Palestinian national, racial and ethnical group".
"This case is important to stop the genocide that is currently happening in the Gaza Strip," Justice Minister Ronald Lamola told national broadcaster SABC as he arrived in The Hague to support the legal team.
Israeli President Isaac Herzog has dismissed the accusations as "atrocious" and "preposterous".
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 cut off diplomatic ties with Israel over the war.
A Hamas attack on Israel on 7 October resulted in about 1,140 deaths in Israel, according to an AFP tally based on official figures.
Israel has since bombarded Gaza by land, sea and air, killing more than 23,000 people, most of them women and children.