South African police were forced to open fire to protect themselves from charging armed protesters at the Marikana mine, Police Commissioner Riah Phiyega said on

Friday.

She told a news conference that 34 people were dead, 78 injured and 259 arrested in Thursday's violence.

Phiyega added that police were saddened by the loss of life in the incident, which came after a week of inter-union violence and strikes at the mine.