China’s iron ore futures hit a five-year high Monday amid worries of short supply from Brazil after iron ore giant Vale reported that another dam faces a risk of rupturing.

The most-traded September 2019 iron ore contract on the Dalian Commodity Exchange rose as much as 4.6% from the previous trading day to 760 yuan ($110) per ton on Monday, extending a strong rally last week.

Iron ore stockpiles in Chinese ports dropped 4.4 million tons from a week ago to 128 million tons as of May. 24, the biggest weekly drop since October 2015, according to industry portal Mysteel.com.

Spot prices are also on the rise, surging 15 yuan to 25 yuan for each ton on Monday, data from the China Iron and Steel Association showed.

The collapse of a Vale mine dam in late January killed more than 230 people in Brazil. Vale said earlier that its 2019 iron ore production is set to decline by as much as 59 million tons from last year’s 366 million tons, partly because of the dam collapse. More than half of Vale’s 2018 production was shipped to China.

Meanwhile, other major iron ore miners including Rio Tinto and BHP have also forecast declining supply this year citing weather factors.

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