There were no serious consequences, Civil Defence Minister Carl-Oskar Bohlin said.

"The Swedish Security Service handled the case and was able to identify the actor behind it, which has ties to Russian intelligence and security services," Bohlin told reporters.

Bohlin told AFP the attack failed "because the security systems in place worked."

Without going into detail, he said the aim of the operation was to disrupt the functioning of a facility that supplies heating.

The minister added that the attack "illustrates that we are dealing with an antagonist who does not hesitate to create physical disruptions that can be likened to sabotage of our physical infrastructure."

The plant was located in western Sweden, he said.

Bohlin said cyber threats against Swedish interests had increased since Russia's full-scale invasion of Ukraine in February 2022, as Moscow targeted countries supporting Ukraine.

"This points to a changed, more risk-prone and more reckless behavior from Russia, which could lead to potentially very harmful effects on society," he said, adding that the Swedish government was taking the development "very seriously".

"Our support for Ukraine remains steadfast," he stressed.

Bohlin also said that attackers were no longer just relying on direct denial of service (DDoS) attacks against IT systems, but were now also targeting the systems that run the infrastructure.

"That is, control systems which often control physical functions in various operations and attempt to destroy, compromise, or disrupt them," Bohlin told AFP.

He said it was important for Sweden to publicise the threats it was facing to send a signal "to threat-actors and let them know that we see what you are doing."

"We are also doing it to continually raise awareness in society, in order to develop our cybersecurity and collective resilience, and so that we can act in solidarity with our allies and partners."