Moscow says the Soviet army freed the Baltic states from the Nazis
Lithuania's parliament has passed the toughest restrictions anywhere in the former Soviet Union on the public display of Soviet and Nazi symbols.
It will now be an offence in the Baltic state to display the images of Soviet and Nazi leaders.
This includes flags, emblems and badges carrying insignia, such as the hammer and sickle or swastika.
Correspondents say equating Soviet and Nazi symbols in this way is certain to infuriate Russia.
The new law also prohibits the Nazi and Soviet national anthems but does not specify if this extends to the modern-day Russian national anthem, which uses the Soviet music with different lyrics.
BBC Russian affairs analyst Steven Eke says these are the toughest bans on symbols from the Soviet past adopted in any of the 15 countries that emerged from the USSR.
The measures go further than neighbouring Estonia's ban on Soviet symbols, he says.
Estonia's decision to put the swastika and hammer and sickle on an equally prohibited footing was described by Russia as "blasphemous", and an attempt to rewrite history.
Moscow's official interpretation of history is that Lithuania, Latvia and Estonia were liberated from Nazi Germany by, then voluntarily joined, the Soviet Union.
This account is rejected by those three Baltic States and most other European nations, says our correspondent.
They believe the Soviet Union illegally occupied the Baltic republics as a result of a secret agreement - the Molotov-Ribbentrop Pact - between the Soviet Union and Nazi Germany.
The occupation continued until the collapse of the Soviet state itself at the end of 1991.