Free City Incident
Having moved to the "Free City" in Russia, the Korean Independence Corps was caught in a struggle for command and forcibly disarmed by the Red Army; many fighters were killed or captured.

Hyun616 · CC BY-SA 4.0 · Source
Expecting Red Army support, the Corps moved early in 1921 to the Free City (Alekseyevsk, today Svobodny). The Shanghai and Irkutsk factions of the Korean Communist Party fought over command of the Korean units, and on 28 June the Red Army, backing the Irkutsk faction, attacked the units that refused to disarm.
The independence armies were badly weakened. The survivors returned to Manchuria and reorganized into the three administrations.