The links are in Finnish because Russians basically jail everyone who tries to make research about people killed in Stalin's purges. The first 3 links are about Kola peninsula Finns.

https://fi.wikipedia.org/wiki/Kuolansuomalaiset

https://yle.fi/uutiset/3-11032865

https://www.hs.fi/ulkomaat/art-2000007816780.html

Other genocides were cultural, and it still means e.g. vepsläižed, inkeroin, and other karelians in Russia exist only in theory. Latvian finns were killed during imperial Russia era.