Pripyat River
Smaller monitors (70–100 ton displacement) were used by Poland in 1939 on the Pripyat River and by the Soviet Union in 1941 on the Pripyat and Dnepr rivers. The Soviet Union also had five "Zheleznyakov"-class monitors of 263 tons, which served with the Danube Flotilla and Dnieper Flotilla in World War II.