Prices for platinum and palladium climbed Tuesday following reports of rising tension in South Africa's mining region.
Platinum for July delivery rose $14.10, or 1 percent, to settle at $1,456 an ounce. Palladium for June rose $8.55, or 1 percent, to $817.30 an ounce.
Three miners working in defiance of a mining strike were killed in separate incidents over recent days in South Africa's platinum belt. The attacks come as mining companies increase efforts to break the four-month strike. One of them, Lonmin, has appealed to workers to return to work and reportedly plans to reopen mines Wednesday.
The strike started Jan. 23 and has squeezed worldwide platinum production. South Africa is the world's top producer of platinum and the second-largest producer of palladium behind Russia.
Other metals were mixed. Gold for June delivery fell $1 to $1,294.80 an ounce, while silver for July ended unchanged at $19.55 an ounce. Copper for July slipped 1 cent to $3.14 a pound.
In other trading, wheat lost 6 cents to settle at $7.09 a bushel. Corn rose 3 cents to $5.03 a bushel. Soybeans rose 19 cents to $14.84 a bushel.
In the market for oil and gas contracts, benchmark U.S. crude oil for June delivery rose $1.11 to $101.70 a barrel on the New York Mercantile Exchange.
In other energy futures trading on the Nymex:
— Wholesale gasoline rose 2 cents to $2.92 a gallon.
— Heating oil rose 3 cents to $2.94 a gallon.
— Natural gas lost 8 cents to $4.36 per 1,000 cubic feet.