The US has issued new sanctions against Russians who it says assisted the Kremlin in developing offensive cyber activities.
Three individuals and five Russian businesses have been placed on the sanctions list by the US Treasury for having provided material and technological support to the Federal Security Service (FSB).
According to the US Treasury, the individuals had been involved in the destructive NotPetya cyber attack which devastated computers in Ukraine and across Europe last year.
They were also involved in a global campaign to compromise network infrastructure devices, including routers and switches, which the head of the UK's National Cyber Security Centre said had affected critical national infrastructure.
The sanctions follow charges filed in February against 13 employees of a Russian troll factory which was accused of attempting to interfere with the 2016 US presidential election.
"Today's action also targets the Russian government's underwater capabilities," said the Treasury, adding: "Russia has been active in tracking undersea communication cables, which carry the bulk of the world's telecommunications data."
Steve Mnuchin, the Treasury Secretary, said the US was "engaged in an ongoing effort to counter malicious actors working at the behest of the Russian Federation and its military and intelligence units to increase Russia's offensive cyber capabilities.
"The entities designated today have directly contributed to improving Russia's cyber and underwater capabilities through their work with the FSB and therefore jeopardise the safety and security of the United States and our allies."
The sanctions mean that all of the property and interests in property held by the individuals and the businesses will be blocked, and people in the US will be prohibited from engaging in transactions with them.
The five businesses named are the Russian firm Digital Security, which the Treasury alleged worked on a project increasing the offensive cyber capabilities of the Russian intelligence services.
Two of Digital Security's off-shoot companies, ERPScan and Embedi, were also sanctioned. ERPScan is a well-known cybersecurity firm with offices in Palo Alto, California.
The Kvant Scientific Research Institute has been sanctioned, with the Treasury stating that its projects were being supervised by the FSB.
Also sanctioned was a business called Divetechnoservices, which "procured a variety of underwater equipment and diving systems for Russian government agencies" as part of the fibre-optic cable interference programme.
More from Russia
The three individuals named in the new sanctions, Aleksandr Lvovich Tribun, Oleg Sergeyevich Chirikov, and Vladimir Yakovlevich Kaganskiy, were all senior staff at Divetechnoservices.
None of the sanctioned parties were immediately able to respond to Sky News for comment. The Kvant Scientific Research Institute could not be reached.