U.S. authorities have seized dozens of Internet domains that Russian intelligence-backed hackers used as part of a sophisticated campaign to gain access to U.S. government computers.

The United States announced the seizure on Thursday of 41 internet domains allegedly used by Russian intelligence agents to try to gain access to the computers and email accounts of Pentagon, State Department and other US government employees.

U.S. authorities have seized dozens of internet domains used by Russian intelligence agents and their proxies, the Justice Department announced.