Combat Organization of the Socialist Revolutionary Party

The Combat Organization (Russian: Боевая организация партии социалистов-революционеров, Boyevaya organizatsiya partii sotsialistov-revolyutsionerov, BO) was the terrorist wing of the Socialist Revolutionary Party (PSR) in the Russian Empire, active from 1902 to 1907. Established by the PSR Central Committee, its primary purpose was to carry out political assassinations against high-ranking government officials to destabilize the Tsarist regime and further the party's revolutionary aims.

Source: Wikipedia — Combat Organization of the Socialist Revolutionary Party (CC BY-SA 4.0)