The Estonian Foreign Ministry said that a Russian icebreaker entered the country's territorial waters without permission, DPA reported.
The incident occurred on Saturday in the area of Vaindlo Island in the Baltic Sea.
The statement from the Estonian diplomatic service states that neither the Foreign Ministry nor the Estonian Navy was informed about the entry of the icebreaker "Murmansk". The vessel did not respond to radio messages sent to it by the Estonian authorities.
"Murmansk" remained in Estonian waters for four minutes.
The Russian chargé d'affaires was summoned to the Foreign Ministry in Tallinn in connection with the case.
"We remind the Russian Federation that clear and unambiguous rules apply in Estonian territorial waters, including during the icebreaking season," Foreign Minister Margus Tsahkna said. He stressed that compliance with these rules is mandatory for everyone to prevent future violations. A foreign ship can exercise its right to innocent passage through territorial waters provided that the country concerned notifies the Foreign Ministry at least 48 hours before entering, the Estonian minister explained.
Given the difficult conditions and the need to provide assistance to ships, Estonia is ready to reduce the notification period to six hours by the end of the winter season, Tsahkna added.