The Latvian military says it has spotted three Russian warships close to its territorial waters.
According to a statement posted by the force on Twitter, three ships identified as the Liven 551, Serpukhov 603 and the Morshansk 824 has been spotted four miles from their territorial waters – and 12 nautical miles from the coast.
Russian newspaper Fontanka reported the sightings came in response to the presence of an American destroyer in the region.
The newspaper said that the Morshansk and a handful of other vessels were lined up around the St Petersburg’s Kronshtadt port but were suddenly redeployed to the Baltic Sea.
It said this is likely to be because of the anticipated arrival of the cruise missile-equipped USS Carney.
The paper suggested that as a result, the planned naval parade for Victory Day - the Russian celebration of the end of World War II - would not happen on Tuesday, Newsweek reported.
But an unnamed Russian military official told state news agency RIA Novosti that the parade was not cancelled but fewer ships would be taking part than had previously been planned.
It follows increased fears that Russia is trying to encroach on the Baltic region after Russian aircraft and vessels were spotted in the area.
Last month Admiral Michelle Howard, the head of Nato's Allied Joint Force Command in Naples and commander of US naval forces in Europe and Africa, said Russian naval activity in Europe now exceeded levels seen during the Cold War.
Nato has stepped up its presence of in the region with four battalions being deployed to Poland, Latvia, Lithuania and Estonia as part of Operation Atlantic Resolve.
In March, the first of 800 UK troops were deployed to Estonia to help deter Russian aggression.
Some 120 soldiers from the 5th Battalion The Rifles landed at the Amari air base, 25 miles south-west of the capital Tallinn.
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