PLATINUM futures have climbed to the highest price in almost three weeks on renewed concern about supply disruptions from top producer South Africa after a shooting at a mining union office. The most actively traded platinum contract, for July delivery, on Monday rose $US35.60, or 2.4 per cent, to settle at $US1,497.40 a troy ounce on the New York Mercantile Exchange, the highest since May 14. Platinum's rise was the largest in percentage terms since September. A member of South Africa's National Union of Mineworkers was killed and another wounded in a shooting at the union's office at platinum miner Lonmin PLC on Monday. Production in South Africa fell 15 per cent last year as strikes rippled through the industry following clashes at Lonmin's Marikana mine beginning in August. "South Africa can change the supply-and-demand balance very quickly," said Adam Klopfenstein, a senior market strategist with Archer Financial Services. "Mining disruptions would support platinum" prices. South Africa accounted for 73 per cent of platinum mine output last year, according to Johnson Matthey, a specialty chemicals company and major platinum user. The NUM said it doesn't know who carried out Monday's shooting. Lonmin said that police were investigating the incident and that the company is "appalled and horrified at this senseless violence." Separately, mining giant Glencore Xstrata on Monday said it had dismissed around 1,000 workers who went on a strike last week at three of its chrome mines in South Africa. They walked off the job over an allegation that management had abused one of the workers, bringing the operations to a near halt. The workers can now appeal their dismissal. Gold also rose on Monday, as an unexpected contraction in US manufacturing weighed on the US dollar. The ICE US Dollar Index touched a three-week low after the data, helping buoy gold. US dollar-denominated gold and the greenback tend to move inversely. Gold prices have been hit this year as an improving US economy and steadying global financial system drew investors to stocks and other assets. A renewed downturn could draw investors looking for a refuge back to gold, traders say. The most actively traded gold contract, for August delivery, rose $US18.90, or 1.4 per cent, to settle at $US1,411.90 a troy ounce on the Comex division of the New York Mercantile Exchange. Settlements (ranges include open-outcry and electronic trading): London PM Gold Fix: $1,402.50; previous PM $1,394.50 Aug gold $1,411.90, up $18.90; Range $1,388.30-$1,416.50 Jul silver $22.721, up 47.8 cents; Range $22.175-$22.915 Jul platinum $1,497.40, up $35.60; Range $1,456.60-$1,505.60 Sep palladium $759.05, up $5.40; Range $748.65-$763.00