Operation Tân ([ˈtɑːn], "fire") was the name of a series of police raids in Wales between 1 October 1979 and 30 September 1980. The aim of the operation was to identify "Welsh extremists" responsible for burning second homes with English owners.
It has been criticised as a more generalised trawl of left and nationalist milieux within Wales.
References
Operation Tân Wikipedia(Text) CC BY-SA