South Africa’s Impala Platinum posted a 17 percent rise in production in the quarter to the end of March thanks to a 71 percent rise in output at its Zimbabwe unit Zimplats, the company said on Tuesday.

Despite a fire at its Rustenburg operation, Implats’ output was steady at 142,000 ounces compared to 143,000 ounces in the same period last year.

But the tonnage milled declined to 2 million tonnes from 2.5 million tonnes the year before and so production at Rustenburg will likely decline this quarter.

At Zimplats, the start of an open-pit operation has helped to compensate for the loss of production at the Bimha mine, which is being redeveloped because of concerns about the stability of its ground and tunnels.