JOHANNESBURG — About 270 miners at the Lonmin Platinum Mine in South Africa were charged Thursday with the murders of 34 striking colleagues who were shot by South African police officers, authorities said, a development that could further infuriate South Africans already shocked and angered by the police action.

The decision to charge the miners comes under an arcane Roman-Dutch common purpose law used under the apartheid regime, and it suggests President Jacob Zuma’s government wants to shift blame for the killings from police to the striking miners.

Firebrand politician Julius Malema, who has seized on the shootings to score political points, told supporters of miners outside the courthouse that the charges were “madness.”

“The policemen who killed those people are not in custody, not even one of them. This is madness,” said Malema, who was expelled from the governing African National Congress in April.

“The whole world saw the policemen kill those people.”

Police Commissioner Gen. Riah Phiyega has been criticized for saying her officers “did nothing wrong.” She said they acted in self-defense, using live bullets only after they were fired upon and had failed to stop a charge of miners with water cannons, stun grenades, tear gas and rubber bullets.

The police killings were the worst public display of state-sponsored violence since apartheid was overthrown and have traumatized a nation that hoped it had seen the last of such scenes.

In the fallout from the killings, the bitter mine strike has strengthened. The mine reported an average of 6.6 percent of workers showed up across various shifts Thursday, down from 13 percent on Monday and 50 percent on Saturday.

The mine said many workers were being intimidated and feared for their safety if they returned to work. it has suffered a serious hit to its share price and has said it probably cannot meet debt payments, due next month, because of the strike that started Aug. 10.