The U.S. Treasury Department slapped economic sanctions on a major yakuza underworld syndicate and its leaders Wednesday, the fourth such Japanese gang to be blacklisted.

The department said it has frozen any assets held by Kudo-kai, its president, Satoru Nomura, and its chief, Fumio Tanoue, within the jurisdiction of the United States. It has also placed a general prohibition on U.S. persons conducting any transactions with them.

Kudo-kai, which is based in Fukuoka and has some 950 members, is reportedly the most violent yakuza syndicate, the department said.

It had previously singled out Japan's largest yakuza crime syndicate, the Yamaguchi-gumi, as well as Sumiyoshi-kai and Inagawa-kai, for similar sanctions.