The Estonian Foreign Ministry said on Friday it had expelled two Russian diplomats, with a local news portal saying the two had been posted at a consulate in the northeastern town of Narva on the Estonian-Russian border.

"We can confirm that Estonia has expelled two Russian diplomats," ministry spokeswoman Sandra Kamilova told AFP. She said that Russia's embassy in Tallin had been informed.

The Baltic News Service named the two men as Dmitry Kazennov, Russia's consul general in the eastern city of Narva and consul Andrey Surgaev. 

The announcement quickly drew a response from Moscow, with TASS news agency citing a Russian Foreign Ministry official as calling it "one more unfriendly and groundless action that will not go unanswered."

Estonia joined NATO and EU in 2004

Estonia, a former Soviet republic that joined NATO and the European Union in 2004, has a tense relationship with its large neighbor Russia, largely owing to the conflict in Ukraine. The country is home to a large Russian minority.

Earlier this month, an Estonian court sentenced a Russian national to five years in prison for spying for Russia's main intelligence directorate, the foreign intelligence unit of the Russian armed forces.

Since NATO reinforced its eastern flank following Russia's annexation of Crimea from Ukraine and the ongoing conflict in the east of Ukraine, Russian intelligence agencies have increasingly probed Estonia’s defenses, according to Estonia’s Internal Security Service.

tj/jm (Reuters, dpa)