LONDON (Reuters) - Western governments jointly warned on Wednesday about a potential threat of increased malicious cyber activity by Russia against critical infrastructure as a response to sanctions imposed as punishment for its invasion of Ukraine.

       The cybersecurity agencies of the United States, Britain, Australia, Canada and New Zealand - which together form the Five Eyes intelligence-sharing alliance - said the war could expose organisations everywhere to cyber crime.

       "This activity may occur as a response to the unprecedented economic costs imposed on Russia as well as materiel support provided by the United States and U.S. allies and partners," the U.S. Cybersecurity & Infrastructure Security Agency (CISA) said in a statement on its website.

       In March, CISA said there was "evolving intelligence" that Russia was exploring options for potential cyberattacks.

       Last week, it said advanced hackers have shown they can take control of an array of devices that help run power stations and manufacturing plants, although that alert did not name Russia, which routinely denies it carries out cyberattacks.

       Wednesday's statement also warned of the potential for cybercrime groups which have pledged to support the Russian government to carry out digital extortion attacks against Western targets.

       "These Russian-aligned cybercrime groups have threatened to conduct cyber operations in retaliation for perceived cyber offensives against the Russian government or the Russian people," the statement said.

       (Reporting by James Pearson; editing by Grant McCool)