Platinum and palladium on Wednesday added to sharp gains made overnight on worries that increasing labour tensions in major producer South Africa could hurt supply, while gold edged up on escalating violence in Ukraine. Platinum edged up 0.4 percent to $1,452.00 an ounce after jumping about 1 percent in the previous session to its highest in a month. Palladium also rose 0.4 percent after rising overnight to a one-week high. Meanwhile, gold edged up 0.2 percent to $1,294.81 an ounce by 0657 GMT. The metal is often seen as a safe-haven investment at times of political uncertainty.