Tens of thousands of South Africans have marched in cities and towns to demand the resignation of President Jacob Zuma, deepening the country's crisis on a day when its credit rating was downgraded to junk status by another major agency.
The anti-Zuma protests were the biggest in South Africa in years. The government estimated that about 60,000 protesters marched on Friday, everywhere from big cities to small towns, although organizers said the number was much higher.
Among those in the protests were members of several opposition parties, many civil-society groups, trade unions, business executives, the ruling party's alliance partners in the Communist Party, and even the 85-year-old Nobel Peace Prize winner, retired archbishop Desmond Tutu, who is in frail health.
Mr. Zuma's fight for survival is inflicting heavy damage on South Africa's economy, with fresh predictions of near-zero growth after Fitch Ratings decided on Friday to follow S&P in downgrading the country's rating into the junk category.
Mr. Zuma's recent purge of his cabinet rivals, including top finance officials, "will weaken standards of governance and public finances," Fitch said in a statement.
It predicted that the sacking of the respected finance minister will accelerate Mr. Zuma's plans for a hugely expensive nuclear-energy project, likely to cost tens of billions of dollars. The project, expected to involve a deal with Russia's nuclear agency, could bankrupt the government, critics say.
Mr. Zuma's party, the African National Congress (ANC), is struggling to stamp out an internal revolt against him. Three of the top six ANC leaders have criticized Mr. Zuma's cabinet purge, but the party closed ranks this week and its leaders agreed to drop their public criticism.
The protests on Friday were largely peaceful, although a small group of ANC loyalists rushed towards the site of an anti-Zuma rally and were forced back by police firing rubber bullets. Several of the ANC supporters were injured.
In a separate incident, a small group of pro-Zuma militants attacked a few dozen protesters who had gathered outside the luxurious suburban mansion of the Gupta brothers, business tycoons who have a controversial partnership with Mr. Zuma's son. An investigation by a South African Ombudsman heard evidence that the Guptas were offering bribes and influencing state contracts and cabinet appointments.
Police used stun grenades to break up the clash between the anti-Zuma and pro-Zuma groups at the gates of the Gupta compound.
In the capital, Pretoria (also known as Tshwane), thousands of protesters marched to the government headquarters, the Union Buildings. In Cape Town, thousands marched to Parliament.
By the government's official estimate, 10,000 demonstrated in Johannesburg, as many as 8,000 in Durban, and 15,000 in Pretoria, along with smaller numbers in other towns and cities. Organizers said the true numbers were twice as high.
The Zuma government was clearly worried by the protests. All week, it has warned that they could be illegal or violent. On Thursday, the Tshwane police force announced that the main march was illegal. Organizers went to court and obtained a ruling to permit the march, but the national police commissioner held a televised news conference on Thursday night and insisted again that the protest was illegal, despite the court ruling.
Tshwane Mayor Solly Msimanga, who belongs to an opposition party, has alleged that ANC supporters on the local police force were trying to sabotage the protests by calling them illegal.
Mr. Zuma's government is also facing trouble on the international stage. On Friday, it was hauled before a hearing of the International Criminal Court in The Hague to answer questions about its refusal to enforce an ICC arrest warrant on Sudan President Omar al-Bashir when he visited South Africa in 2015. It was the first-ever public hearing into an ICC member state's failure to comply with an ICC arrest order.
South Africa allowed Mr. al-Bashir to attend a regional summit in Johannesburg and refused to arrest him, even though ICC member states are usually required to enforce the court's arrest warrants. The ICC has indicted the Sudanese President for war crimes and genocide for his actions in Darfur.
At the hearing, South Africa insisted that it had to respect the "immunity" of state leaders, and it denied that it had violated its ICC obligations. But court prosecutors said South Africa's explanations were "shifting" and contradictory. They demanded that South Africa be reported to the ICC's assembly or the United Nations Security Council for punishment for a serious breach of the court's rules.