The corvettes – Liven 551, Serpukhov 603 and Morshansk 824 – were detected only four nautical miles from Latvian territorial waters.
It was the latest in a series of moves by Vladimir Putin’s naval forces seen as testing the response of the small Baltic state, a NATO and EU member.
The move on Sunday was linked today to the arrival in the Baltic Sea of US warship, USS Carney, with cruise missiles on board.
The three Russian vessels had been deployed to St Petersburg ahead of the country’s annual war commemoration on 9 May, known as Victory Day.
But they suddenly left again for deployment in the Baltic, according to news agency Fontanko.ru