Three Russian support vessels were spotted off the coast of Scotland on 4 March by observers using the Marine Traffic tracking app.
The vessels are known to act as escorts to the Russian Navy’s new Admiral Gorshkov-class frigates, two of which have so far been completed.
At least one of the new frigates is reported to have been fitted with the Fillin 5P-42 weapon, a “visual optical interference” device designed to cause “dizziness, nausea and feelings of disorientation” among its targets.
The Royal Navy said on Wednesday that the Type 45 destroyer HMS Defender was shadowing the Russian naval task group along the coast of the UK.
Armed Forces Minister Mark Lancaster said: “The Royal Navy is always standing ready to defend the UK."
The SNP claimed frequent stops by Russian vessels off the coast of Scotland underline the need for Royal Navy surface vessels, all of which are based on the Channel Coast, to operate out of ports further north.
SNP Defence spokesperson Stewart McDonald said: “The UK’s Ministry of Defence is failing Scotland, allowing Russian navy vessels sailing through our territorial waters at will to conduct provocative drills like this.
“Sightings of this new class of Russian Navy vessel also underline why years of treating Russian threats as a joke are over and it is unacceptable that it takes over 24 hours for the Royal Navy to respond to threats in Scottish waters from bases on the South Coast of England."