An even bloodier wave of pogroms broke out from 1903 to 1906, at least some of them believed to have been organized by the Tsarist Russian secret police, the "Okhrana". They included the Białystok pogrom of 1906 in the Grodno Governorate of Russian Poland, in which at least 75 Jews were murdered by marauding soldiers and many more Jews were wounded. According to Jewish survivors, ethnic Poles did not participate in the pogrom and instead sheltered Jewish families.