Socialist study circles ("kruzhki") began to emerge in Russia during the decade of the 1870s, populated primarily by idealistic students in major urban centers such as St. Petersburg, Moscow, Kiev, and Odessa. These initially tended to have a loose organizational structure, decentralized and localized, bound together by the personal familiarity of participants with one another. Efforts to propagandize revolutionary and socialist ideas among factory workers and peasants were quickly met with state repression, however, with the Tsarist secret police ("Okhrana") identifying, arresting, and jailing agitators.