Lithuania on Wednesday launched the trial of 65 former Soviet officials over a deadly 1991 crackdown by Moscow during he Baltic state's independence drive.
"All these people are accused of crimes against humanity and war crimes," prosecutor Daiva Lisauskiene told reporters.
Only two suspects, both Russian citizens, attended the hearing, a quarter century after the massacre in which 14 civilians died and 700 were injured.
Former tank officer Yuri Mel has been held in Lithuanian custody since being detained at a checkpoint on the border with Russia's exclave of Kaliningrad in 2014.
Another suspect is a Vilnius resident who is reportedly cooperating with justice authorities.
The remaining defendants -- citizens of Belarus, Russia and Ukraine -- were represented by their lawyers.
Lithuanian prosecutors also sought to question ex-Soviet leader Mikhail Gorbachev as a witness, but Moscow refused to cooperate with the case.
Soviet troops entered the capital Vilnius to bring Lithuania to heel after its 1990 secession from the Soviet Union following five decades under Moscow's thumb as a republic of the USSR.
The troops stormed the city's television tower as tens of thousands of people formed human shields to block their progress.
The breakaway republic played a key role in the demise of the Soviet Union in December 1991.
Russian President Vladimir Putin once described the collapse of the USSR as the "greatest geopolitical catastrophe" of the 20th century.
Lithuania has been seeking justice for the crackdown's victims ever since the Baltic state won recognition as an independent nation in September 1991.
Six Soviet-era Lithuanian officials were convicted and jailed in the 1990s for their role.
The war crimes probe gathered steam in 2010 thanks to a change in Lithuania's criminal code, allowing the trial of individuals in absentia when they are abroad and cannot be extradited.
President Dalia Grybauskaite on Wednesday hailed the move, but said it was belated.
"It's a partial step in the direction of achieving justice," independence icon Vytautas Landsbergis told AFP, explaining that even if the defendants are found guilty, Russia will never extradite them for sentencing.
Relations between Vilnius and Moscow have long been rocky, notably since Lithuania joined the European Union and NATO in 2004.