 Complete the following phrase:  At the end of 1942, three other small ghettos operated in the area: Astravyets District, Smarhon District, and Ashmyany. Due to increased partisan activities, it was decided to liquidate the four ghettos in spring 1943. To minimize resistance, Jewish policemen from Vilnius Ghetto were brought in to facilitate the operation. About 2,700 able-bodied Jews were transferred to Vilnius Ghetto or work camps in Žiežmariai, Žasliai, or Kena. On April 4, the remaining Jews boarded onto a freight train in Švenčionėliai. They were told that they would be transported to Kaunas Ghetto. Instead, the train stopped at 