One of the world’s biggest aluminium producers has switched to manual operations at its smelting facilities following a cyber-attack.
Hydro, which employs more than 35,000 people in 40 countries, says the attack began on Monday night and is ongoing.
A spokesman told the BBC that he could not yet confirm what type of cyber-attack the Norwegian firm was facing, or who was behind it.
The company’s website is currently down and it is posting updates to Facebook.
“IT systems in most business areas are impacted,” the firm said.
Hydro told the BBC that digital systems at its smelting plants were programmed to ensure machinery worked efficiently.
However, these systems had had to be turned off.
“They are much more reliant today on computerised systems than they were some years ago,” a spokesman said.
“But they have the option of reverting back to methods that are not as computerised, so we are able to continue production.”
Smelting operations in Norway, Qatar and Brazil had been affected, according to the Reuters news agency. Additionally, Hydro had shut down some of its smaller metal extrusion plants.
The firm said it was working to contain and “neutralise” the attack.
Norway’s state cyber-security agency is also helping Hydro to respond to the incident.
Huge aluminium plants hit by cyber-attack