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.

NATO will deploy additional warships, drones and rapid-reaction rules in the Baltic Sea after Estonia forced a suspected Russian “shadow-fleet” tanker out of its waters and a Russian fighter briefly violated NATO airspace,