UK tracked 3 Russian subs in alleged N. Atlantic 'covert' op

London: Britain said Thursday 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 Defense 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."

Healey said he was unveiling details of the monitoring operation, which involved British warships and military aircraft, "to call out this Russian activity" and send Putin a message.

“We see your activity over our cables and our pipelines, and you should know that any attempt to damage them will not be tolerated and will have serious consequences,” he added.

Britain and its allies monitored an Akula-class Russian nuclear-powered attack submarine and two specialist submarines from Russia's Main Directorate of Deep Sea Research (GUGI), as they sailed "in and around wider UK waters", according to Healey.

The attack sub was "a likely decoy to distract" from the other two vessels, which are "designed to survey underwater infrastructure during peacetime and sabotage it in conflict", he said.

UK warships dropped sonar buoys "to demonstrate to them that we were monitoring every hour of their operation", the defense secretary added.

“We wanted to ensure that we could warn them that their covert operation had been exposed and reduce the risk that they may attempt any action that could damage our pipelines or our cables,” he said.

"I'm confident we have no evidence that there has been any damage."

The mission involving around 500 British personnel saw UK aircraft fly more than 450 hours while a navy frigate covered several thousand nautical miles, Healey said.

Separately, he responded to criticism in the Daily Telegraph that London was not making good on recent threats to stop sanctioned vessels from Russia's sanctions-busting "shadow fleet" from transiting through UK waters.

It followed the newspaper photographing a Russian frigate escorting at least one sanctioned Russian-linked tanker through British waters this week without interference from the UK navy.

“We have the military options and we're ready... to interdict shadow fleet vessels,” Healey said.

He added London's stance was "making Russia reroute its shadow ships... or escort its shadow ships with its own warships" and thereby "making it harder for Putin to pursue his illegal oil revenues."

"We aim, with others, to put more pressure in the coming weeks and months on that activity."