Yad Vashem is increasingly concerned over growing Holocaust revisionism and anti-Semitism in Lithuania, the Holocaust Memorial announced Monday. The unusual public rebuke comes a day after swastikas and anti-Semitic graffiti were found spray-painted on the walls of the Jewish community centers in central Vilnius, and Lithuanian authorities press ahead with investigations into Jewish Holocaust survivors for their wartime activities as partisans in Lithuania. "It seems that the harmful phenomenon of historical revisionism and distortion, of which the investigation of the Jewish partisans is a prime example, may actually be increasing in your country," Yad Vashem chairman Avner Shalev wrote in a August 10 letter to Lithuanian Prime Minister Gediminas Kirkilas asking for his direct intervention. "Only by dealing openly and forthrightly with the full and complex truth about the past will your nation succeed in building for itself a secure and stable future," the letter read. Among the Holocaust survivors under Lithuanian investigation is Dr. Yitzhak Arad, a Holocaust historian and former chairman of the Yad Vashem directorate. Lithuania opened a criminal investigation into Arad last year on suspicion that he took part in the murder of Lithuanian civilians during the Holocaust. The investigation came to light when the Lithuanian prosecutor's office sent the Israeli Justice Ministry a request to interrogate Arad in the wake of his memoir, in which he describes his experiences as a partisan in Nazi-occupied Lithuania. "It is clear that initiating criminal proceedings into Dr. Arad's involvement in Lithuanian partisan activity during World War II is tantamount to a call for an investigation into all partisan activity," Shalev wrote in a previous letter to visiting Lithuanian Foreign Minister Petras Vaitiekunas earlier this year. During the Holocaust, most of the Jews of Lithuania were murdered by local citizens. The "Order Police" began to massacre Jews as soon as the Soviets left in 1941, before the German occupation. Out of a prewar population of 220,000, only a few thousand Jews survived the war in Lithuania, representing the largest percentage of Jews murdered in one country during the Holocaust. The Lithuanian capital - a one-time preeminent center for rabbinical studies dating back to the 16th century - is today home to about 5,000 Jews. Separately, the chief Nazi-hunter of the Los Angles-based Simon Wiesenthal Center has accused the Lithuanian authorities of failing to adequately respond to several recent anti-Semitic provocations as well as protecting local Nazi war criminals from prosecution and instead harassing Jewish anti-Nazi Soviet partisans. "Given the woefully inadequate response by the government to the neo-Nazi march through the center of Vilnius less than half a year ago, I believe that the time has come for unequivocal, resolute and immediate action to identify and punish those responsible for this anti-Semitic attack," Dr. Efraim Zuroff wrote in a separate letter to the Lithuanian Ambassador to Israel Asta SkaisgirytÃ©-LiauskienÃ¨. "There is no doubt in my mind that these outbreaks of anti-Jewish violence are the direct result of Lithuania's failure to punish its Nazi collaborators, the recent campaign against Soviet Jewish partisans and the ongoing efforts to minimize the role of Lithuanians in the mass murder of their Jewish neighbors during the Holocaust." "Today's anti-Semitic violence is the direct result of ignoring the crimes of the past," the letter concluded.