Britain said yesterday it had tracked and “seen off” three Russian submarines on an alleged month-long “covert operation” in Atlantic waters “north of the UK” near vital undersea cables and pipelines.

Disclosing details of the joint mission with Norway and other unspecified allies, British Defence Secretary John Healey said there was no evidence the Russian vessels had damaged the subsea infrastructure.

“I deployed our armed forces to track and to deter any malign activity by these vessels,” Healey told a Downing Street news conference.

“Our armed forces left them in no doubt that they were being monitored, that their movements were not covert, as (Russian) President (Vladimir) Putin planned and that their attempted secret operation had been exposed.”