"The murder charge against the current 270 suspects... will be formally withdrawn provisionally in court on their next court appearance," said advocate Nomgcobo Jiba, the national deputy director of public prosecutions.

"Other provisional charges will remain."

The workers were arrested for public violence on August 16 after 34 of their colleagues were gunned down by police at the Lonmin mine in Marikana. Another 78 were injured.

Last week, prosecutors announced that the arrested men would also face murder and attempted murder charges.

Unions, civil society, law experts and political parties roundly condemned the decision.

Justice Minister Jeff Radebe said he would seek clarity on the reasons for the move.

"The protesters are to be released conditionally on a warning and their case postponed pending the finalisation of investigations, including the investigations by the commission," said Jiba.

She was addressing reporters in Pretoria.