The Nikolayevsk incident (尼港事件 Niko Jiken) was a series of events from February through March 1920 during the Allied intervention in the Russian Civil War, culminating in the massacre of several hundred Japanese expatriates and most of the Russian inhabitants of the town of Nikolayevsk-on-Amur in the Russian Far East. In late May, as a Japanese relief expedition approached, Triapitsyn executed all of the remaining inhabitants of the town, both Japanese and Russian, and burned the town to the ground.