Estonia said on Thursday that Moscow had briefly sent a fighter jet into NATO airspace over the Baltic Sea during an attempt to stop a Russian-bound oil tanker thought to be part of a shadow fleet defying Western sanctions on Moscow.

Russia deployed a fighter jet in NATO airspace this week after Estonia tried to inspect a so-called shadow fleet tanker passing the EU-member’s economic area, Estonia’s Foreign Minister Margus Tsahkna said.

Estonia has accused Russia of creating a "serious threat" to NATO in the Baltic Sea after a Russian fighter jet disrupted operations by the Estonian Navy to inspect an unflagged tanker that is on the United Kingdom's sanctions list.