Iron-ore advanced to the strongest level since the middle of October as heavy rains disrupted southeastern Brazil’s iron-ore industry, with the world’s No. 2 producer Vale among companies halting operations and regulators sent to monitor the impact on tailings dams.

Vale has partially suspended services on the Estrada de Ferro Vitoria a Minas railway as well as production at its southeastern and southern systems “to guarantee the safety of its employees and communities,” the Rio de Janeiro-based supplier said in a statement Monday.

Gerdau, Cia. Siderurgica Nacional and Usinas Siderurgicas de Minas Gerais also suspended operations in Minas Gerais this week. While the region represented 40% of Vale’s output in the nine months through September, the company reiterated production guidance of 320-million to 335-million tons in 2022. Output may now be at the low end of the range, analysts said.

The deluge in Minas Gerais state provides fresh impetus to global prices of the steelmaking ingredient, which are up more than 50% since the middle of November. It’s also sounding alarms for tailings dams given the region was the site of two disasters in the past six years including a 2019 collapse that left 270 dead and cost Vale its title of the world’s No. 1 supplier.

On the demand side, traders are monitoring the spread of the omicron variant in top consumer China, with the northern port city of Tianjin a center of infection. Goldman Sachs Group Inc. cut its forecast for the country’s growth this year to 4.3% from 4.8% due to the difficulty of containing the variant.

Support for prices has also come from restocking by mills before the Lunar New Year holiday, which starts on January 31.

Spot prices for iron ore are expected to stay firm, Mysteel Research & Consulting said in a note on Wednesday, citing higher activity from blast furnaces, restocking by mills and interrupted supplies from Brazil.

Iron ore futures in Singapore were up 1.8% at $130.55 a ton by 3:12 p.m., the highest intraday level since October 12. Dalian iron ore futures climbed 1.9%, while rebar and hot-rolled coil advanced at least 0.7% in Shanghai.