Lithuanian prosecutors on Tuesday called for five Russians, including an ex-defence minister, and a Belarusian to be sentenced to jail in absentia over a 1991 Soviet crackdown on the Baltic state's independence drive.
In a move that threatens to further strain bilateral ties, prosecutors said the former Soviet officials, including 93-year-old former defence minister Dmitry Yazov, were guilty of war crimes and crimes against humanity.
"Prosecutors... ask the court to convict the accused of war crimes and crimes against humanity and hand them the strictest punishment which is life imprisonment," prosecution spokeswoman Elena Martinoniene told AFP.
Moscow has described the trial as "illegal" and rejected requests to extradite the suspects and question ex-Soviet leader Mikhail Gorbachev, who is 87.
All six suspects were senior Soviet officials during a January 1991 attack on a Vilnius television that left 14 civilians dead and more than 800 people injured.
Soviet troops had 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.
Prosecutors are also seeking jail terms ranging from 12 to 20 years for another 61 defendants.
Only two suspects are standing trial. Others are being represented by public defenders.
Ever since Lithuania won recognition from Moscow as an independent state in September 1991, it has sought justice for the victims of the crackdown.
While several Lithuanian Soviet-era officials have been convicted, other suspects have remained out of reach in Russia and Belarus.
The Baltic state of 2.8 million people has had a rocky relationship with Russia since independence, and in particular since Lithuania joined the European Union and NATO in 2004.