Russia arrested a suspected Lithuanian spy on Thursday, a court spokeswoman said, adding to a list of espionage allegations as tensions grow between Moscow and the Baltic states it once governed.
Lithuania, a former Soviet republic with a significant ethnic Russian minority, has complained of increased Russian military activity since Moscow annexed Ukraine's Crimea region last year.
Court spokeswoman Yulia Skotnikova named the suspected spy as Yevgeny Mataytis, a citizen of both Russia and Lithuania.
"Mataytis is suspected of gathering secret information and sending it abroad, he has been arrested," news agency Interfax reported her as saying.
Lithuania has said it caught at least four spies working directly or indirectly for Russia in 2014 and so far this year.
Vilnius said in May it had detained an employee of Russia's Federal Security Service who had been trying to infiltrate the country's leadership and security forces. Weeks later, Russia arrested a man it said was a Lithuanian military intelligence officer in Moscow.
Mataytis will be detained for two months, Skotnikova said. He faces a prison term of 10 to 20 years if found guilty of espionage under Russian law.
Along with its fellow Baltic states Latvia and Estonia, Vilnius wants a permanent NATO troop presence on its soil to counter what it sees as an increasing threat from Russia, once dubbed "a terrorist state" by Lithuania's President Dalia Grybauskaite.