JOHANNESBURG — South Africa’s top prosecutor announced Sunday that she is withdrawing controversial murder charges against 270 miners for the killings of 34 striking co-workers shot to death by police.

Meanwhile, the National Union of Metal Workers demanded suspension of officers responsible for the shootings.

Sunday’s announcement follows a sharp criticism from political parties, trade unions, civil society, and legal scholars.

Even the justice minister challenged the prosecutor’s decision to charge the arrested miners under an apartheid-era law that opened President Jacob Zuma’s government to charges that it was acting like the former brutal white rulers.

Nomqcobo Jiba, the acting director of public prosecutions, did not say why she had reversed her decision to shift the blame from the police to the miners.

She said the miners would be freed from jail with a warning, providing police could verify their home addresses.

She said other charges, including public violence, illegal gathering, and illegal possession of firearms, would remain, but the cases were being postponed pending final investigations and the findings of a judicial commission of inquiry, which is to report to the president by January.

Most of the 270 miners were arrested Aug. 16 after police opened fire on striking miners, killing 34 and wounding 78.

The shootings, the worst display of state violence since apartheid ended in 1994, shocked the nation.