 In order to select the particular Germans to be expelled, police used a rationing system which was originally introduced by Germans at the Invasion of Poland and which also allocated food to the recipients by race and ethnicity .At around 6 pm on 29 May 1945, police and assistance troops started to gather all recipients of food coupons marked with a "D" (for Germans) and at around 10 pm on 30 May the first groups of Germans were forced to march south towards the Austrian border.According to police reports, 18,072 Germans were expelled.