LONDON — Russian hackers are seeking to “disrupt or destroy” Britain’s critical infrastructure and not enough is being done to stop them, U.K. government officials said Wednesday.

Britain’s National Cyber Security Centre issued an official threat notice to operators of Britain’s electricity, water and other critical systems, telling them to boost their defenses.

Cabinet Minister Oliver Dowden said the threat comes from hackers sympathetic to Russia though not necessarily directed by the Russian state. He described them as the cyber equivalent of the Wagner Group, the private Russian company with mercenaries fighting in Ukraine. He said that while the alleged hackers lack the capacity to do widespread damage, the threat is growing.