Tens of thousands of demonstrators marched through Cape Town on Saturday to protest what they called Israel’s military assault on Palestinians in Gaza, in one of the biggest rallies in the city since the end of apartheid. Israel has been battling Hamas rocket attacks and cross-border tunnels for the past month.

Demonstrators carried posters stating “Israel is an apartheid state” and “Stop Israeli murder.”

Criticism of Israel is not new in South Africa, and the Jewish state has previously expressed its outrage at comparisons of its policies towards Palestinians with the racist apartheid system.

“We estimate there are well over 30,000 people, and the figure could be as high as 50,000,” Cape Town’s executive director for safety and security Richard Bosman told the national Sapa news agency.

Chanting “Free Palestine” — with some demonstrators wearing t-shirts reading “Africa understands colonialism” — the protesters marched through the center of the city to the national parliament.

The march was called by the National Coalition for Palestine, which groups more than 30 religious and civil society organisations, trade unions and political parties.

Among them are the youth league of the ruling African National Congress and its alliance partner the Congress of South African Trade Unions, as well as the Muslim Judicial Council.

The group said it was demanding “decisive action from the South African government against the Israeli attacks, killings, displacement and destruction of the Gaza Strip.”

There have been calls from several organizations for Pretoria to expel the Israeli ambassador.

Almost 2,000 people have been killed in Gaza over the past month; Israel says 750-1,000 of them are Hamas and other gunmen, and blames Hamas for all civilian deaths since the Islamist terror group which governs Gaza built its rocket launchers, tunnel entrances and other elements of its war machine in residential areas.