A NAVY patrol ship from Portsmouth was called out to intercept a group of Russian warships over the bank holiday weekend.
HMS Mersey was called to locate and monitor the ships as they passed through the English Channel.
They intercepted the intelligence ship Vasily Tatishchev, the depot ship PM82 in company with a Russian tug and the frigate Severomorsk.
Mersey later handed over to Type 23 frigate HMS Iron Duke to escort the Severmorsk out of UK waters.
Lieutenant Commander George Storton, HMS Mersey’s commanding officer, said: ‘HMS Mersey was ready to respond within a matter of hours to this tasking.
‘This is routine business for the Royal Navy, and HMS Mersey herself is well-versed in this role with this being the fourth such operation in the last two months.
‘Mersey is a resilient ship with a versatile crew at notice to respond to incidents ranging from illegal fishing through to people trafficking and drugs smuggling.’
Mersey is one of four River-class patrol ships, three of which conduct fishery protection, general patrols and other maritime security duties around the UK.
A fourth, HMS Clyde, is permanently deployed to the Falkland Islands.
Earlier this year Type 23 frigate HMS Somerset shadowed a surfaced Russian Kilo-class submarine Krasnoda.
The diesel-electric boat was passing through the through the Dover Strait in early May.