The Holocaust in Lithuania: Lithuanian Nazis and local police begin a mass execution of 403 Jews in Nemenčinė.

The Holocaust resulted in the near total eradication of Lithuanian (Litvaks) and Polish Jews^[a] in Generalbezirk Litauen of the Reichskommissariat Ostland in the Nazi-controlled Lithuania. Of approximately 208,000–210,000 Jews at the time of the Nazi invasion, an estimated 190,000 to 195,000 were killed before the end of World War II, most of them between June and December 1941. More than 95% of Lithuania's Jewish population was murdered over the three-year German occupation, a more complete destruction than befell any other country in the Holocaust. Historians attribute this to the massive collaboration in the genocide by the non-Jewish local paramilitaries, though the reasons for this collaboration are still debated. The Holocaust resulted in the largest loss of life in so short a period of time in the history of Lithuania.

Nemenčinė is a city in Vilnius district municipality, Lithuania, it is located only about 7 kilometres (4.3 mi) north-east of Vilnius. Close to Nemenčinė forest was planted which forms a sentence Žalgiris 600 visible from the air.

September 20 is the 263rd day of the year in the Gregorian calendar; 102 days remain until the end of the year.