Russian hackers briefly took control of a dam in Norway earlier this year, the head of the Nordic country's counterintelligence agency has revealed.
The hackers opened a flood gate at the dam in Bremanger, western Norway, on April 7, and released 500 litres of water per second for 4 hours before the attack was detected and stopped, authorities previously said.
No-one was injured during the attack.
Russia's involvement in the attack was revealed in a speech by Beate Gangås, the head of Norway's PST security police agency.
"Over the past year, we have seen a change in activity from pro-Russian cyber actors," she said, adding that the incident at Bremanger was one such activity.
Her comments marked the first time Oslo has officially attributed the cyber attack to its neighbour.
Norway produces most of its electricity via hydropower dams, and intelligence authorities have previously warned of the risk of attacks on its energy infrastructure.
"The aim of this type of operation is to influence and to cause fear and chaos among the general population," Ms Gangås said.
"Our Russian neighbour has become more dangerous."
In an email to Reuters, the Russian embassy in Oslo said the declarations were "unfounded and politically motivated".
Last September, Britain's spy chief accused Russia of waging a "staggeringly reckless campaign" of sabotage in Europe, partly to scare European countries from helping Ukraine. Moscow denies the allegation.
After her speech, Ms Gangås told Reuters that she was going public with the attribution to warn the general population and to try to prevent Russia from launching further attacks.
"I want Norwegians to be prepared," she said in an interview.
NATO member Norway shares a border with Russia in the Arctic. Like the other Nordic countries, it is a staunch supporter of Ukraine.
It is also Europe's largest supplier of gas, which is mostly transported via a network of pipelines under the North Sea.
Reuters/ABC
