Berichah(Or "Bricha"--Hebrew "flight"), the movement after WWII which organized groups of Holocaust survivors to escape from eastern Europe to the West and from there to reach Palestine.
Abba Kovner, partisan fighter and poet, was one of the early organizers. Jews fled from eastern Europe through Czechoslovakia and Romania to Italy, Austria and Germany. In the wake of the pogrom in Kielce, Poland on July 4, 1946, when 42 Holocaust survivors were murdered, a large number of Jews, around 95,000, fled Poland. This flood overwhelmed the Bericha organization. The approximately 250,000 Jews who used the Bericha routes made it the largest organized illegal mass movement in modern times.
Source: Encyclopedia of Holocaust.