A day after South African police shot dead at least 30 strikers, officers say they fired in self-defense at the Marikana mine in the northeast. Protesters allegedly charged them with machetes, clubs and firearms, at which point police say they used tear gas and stun grenades to try to break up the group. When that failed, they opened fire. South African President Jacob Zuma rushed to the site of the shooting Friday. The platinum mine has been at the center of a pay dispute worsened by tensions between two rival trade unions.