LONDON (REUTERS) - Russia was behind a massive cyberattack against a satellite Internet network which took thousands of modems offline at the onset of the war in Ukraine, Britain and the European Union said on Tuesday (May 10).

The digital assault against Viasat's KA-SAT network in late February took place just as Russian armour pushed into Ukraine and helped facilitate President Vladimir Putin's invasion of the country, the Council of the EU said in a statement.

"This cyberattack had a significant impact causing indiscriminate communication outages and disruptions across several public authorities, businesses and users in Ukraine, as well as affecting several EU Member States," the statement said.

A British Foreign Office statement quoted Foreign Secretary Liz Truss as saying the cyberattack was a "deliberate and malicious attack by Russia against Ukraine".

Russia's primary target in the attack was the Ukrainian military, but it also disrupted wind farms and internet users in central Europe, the statement said, citing Britain's National Cyber Security Centre (NCSC).

The Foreign Office statement cited "new UK and US intelligence" which suggested Russia was behind the cyberattack, without elaborating.

The remote sabotage caused a "huge loss in communications in the very beginning of war," Ukrainian cybersecurity official Victor Zhora said in March.

Russia routinely denies it carries out offensive cyber operations. The Kremlin did not immediately respond to a request from Reuters for comment.

Western intelligence agencies, including the US National Security Agency, French government cybersecurity organisation Anssi, and Ukrainian intelligence were investigating Russia's potential role in the attack in the days after it, Reuters reported at the time.