Impala Platinum Holdings Ltd. (IMP) may have to raise pay even...

Impala Platinum Holdings Ltd. (IMP) may have to raise pay even as energy costs surge or face prolonging an almost four-week closure of the world’s biggest mine for the metal after selective wage increases triggered violent riots.

In the past week protesters set fire to cars, barricaded roads and attacked miners going to work with axes, traditional fighting sticks and stones at the mine near Rustenburg, 105 miles (170 kilometers) northwest of Johannesburg. The unrest follows Impala’s firing of 17,200 people striking illegally. Three have been killed and more than 100 arrested in the violence