Wikipedia says that
81 and 88 people were killed by soldiers of the Imperial Russian Army, the Black Hundreds and the Chernoe Znamia
and lists Chernoe Znamia among the "perpetrators" in the infobox. But there's no other reference to this anarchist group (also called "Black Banner") in the article other than mentioning that it had a "strong organization" in the city, and there's no citation given for the claim. In fact, the Wikipedia article about Chernoe Znamia itself says that the group had many Jewish members.
What's going on here? Is this just random misinformation that got put there to discredit anarchists? Or was this a real thing and just badly cited on the Wikipedia page?
I think it is highly unlikely that the Chernoe Znamia participated in the pogrom. The organization did have a Jewish majority, many of whom would have become anarchists due to discrimination and anti-semitism within the Russian Government. I think that what the Wikipedia article is trying to say is that in many ways the pogrom was a response to Chernoe Znamia terrorist activity.
From Paul Avrich’s The Russian Anarchists:
The plight of the Jews grew desperate. Crowded into ghettos, subjected to religious persecution, largely barred from higher education and professional careers, their traditional occupations increasingly circumscribed, the Jews faced the total collapse of their economic and social structure…It was here in the borderlands of the west and the southwest, and chiefly in the Jewish towns, that the Russian anarchist movement was born. (Avrich, 16-17)
Bialystok was a center of the labour movement, and the majority of the anarcho-terrorists in Bialystok were young Jewish people who were dissatisfied with the Bund and other socialist parties. A series of pogroms had begun in Russia in 1903. Many of these young extremists had looked about themselves at the violence and the discrimination that they faced and had decided that the authoritarian state and the bourgeoisie needed to be destroyed, and it needed to be destroyed now. They believed that the socialists were not acting quickly enough, so they struck out on their own.
The Chernoe Znamia believed that through extreme violence--propaganda of the deed--they could tear down the state and the capitalist system and replace it with a libertarian society. They believed in “motiveless terror”. Anyone deemed to be a supporter of the government or capitalism could be executed at any moment with little to no justification required. From Thou Shalt Kill: Revolutionary Terrorism in Russia, 1894-1917 by Anna Geifman: “any terrorist act, without distinction, contributed to the destruction of the bourgeois world in its own way,” (Geifman, 128). Bombings and assassinations were an almost daily occurrence in Bialystok in 1905-1906.
Anti-semitic Russian government officials and newspapers blamed the entirety of the Jewish community for this terrorism and revolutionary behavior. Simon Dubnow in History of the Jews in Russia and Poland states:
Three Duma deputies left at once for Bialystok, and on their return submitted to the Duma an unvarnished account which incontrovertibly established the fact that the Bialystok crime had been carefully prepared as a counter-revolutionary act, and that the peaceful Jewish population had been pitilessly shot down by the police and soldiery.
The pogrom in Bialystok was organized and carried out by Imperial Russian government officials. I find it unlikely that the extremist anti-government Chernoe Znamia would have ever worked alongside soldiers and police officers. It is more plausible to me that the attacks were carried out as a form of retaliation against the terrorists.