— Belsat in English (@Belsat_Eng) August 11, 2017
On 11 August 1937 NKVD chief Nikolai Yezhov issued Order Nr 00485 which gave the go-ahead for mass arrests of persons of Polish origin on charges of espionage in favour of Poland and alleged membership of a Polish military organisation.
Purges affected mainly Poles living in Belarusian and Ukrainian SSR. In total, over 111,000 Poles were executed, more than 28,000 were sent to prison camps. Bodies of Poles killed in NKVD torture chambers were buried in mass graves in Kuropaty near Minsk
The so-called ‘Polish operation’ was the biggest ethnic operation carried out by the NKVD. Finns, Latvians, Greeks, Bulgarians, Koreans, Chinese people and others were also subject to repression. It was part of the Great Terror which targeted millions of Soviet citizens.