Russian cyberoperatives have attacked Britain’s media as well as its telecommunications and energy sectors over the past year, according to prepared remarks by the head of the government’s main cyberdefense agency.

In a speech scheduled for Wednesday in London, Ciaran Martin, chief executive of the National Cyber Security Centre (NCSC), declined to provide any details on the attacks.

The remarks follow Prime Minister Theresa May’s comments Monday in which she accused Russia of spreading disinformation and meddling in elections, echoing a heated debate in the United States over alleged Russian interference in the 2016 presidential race.

Russia has strongly denied any election interference in the United States. The Russian Embassy in Washington did not immediately respond for comment on Martin’s remarks.

The NCSC, a branch of the U.K. signals intelligence agency GCHQ, has been in operation for a year and is charged with shoring up cybersecurity by working with a wide range of stakeholders.

Martin said in his prepared remarks: “I can confirm that Russian interference, seen by the National Cyber Security Centre over the past year, has included attacks on the U.K. media, telecommunication and energy sectors.”

The agency was “actively engaging with international partners, industry and civil society” to tackle the threat from Russia, he added.

Martin echoed May’s comments that Russia was trying to “undermine the international system” through the use of information warfare and cyberattacks.

Cybersecurity experts have long worried about attacks — especially on electrical grids — but Martin offered no evidence that the alleged Russian attacks succeeded in compromising British power systems and other critical infrastructure.