gangster roundup; yakuza crackdown
Refers to a police operation or campaign specifically targeting organized crime groups (暴力団). Often used in news contexts.
The police carried out a large-scale gangster roundup.
暴力団 means 'organized crime group' or 'yakuza group'; 暴力団狩り is the act of rounding them up.
狩り means 'hunting'; as a suffix it can mean a roundup or crackdown, as in 暴力団狩り or 魔女狩り (witch hunt).
Compound of 暴力団 (organized crime group) and 狩り (hunting, roundup).