Japanese credit card holders hit by security breach in U.S.

At least 30 credit card holders in Japan have been hit by fraudulent transactions resulting from the security breach announced Friday in the United States by MasterCard International Inc., according to industry officials.

UFJ Card Co., a unit of one of the nation's largest banks, said Monday there were at least 20 cases both at home and abroad in which information from UFJ MasterCard users was fraudulently used. In addition, UCS Co., a credit card firm affiliated with supermarket chain Uny Co., said it suspects data on 139 individuals with cards linked to MasterCard had been breached and that five of the cases led to financial damage.

Six cards issued by regional banks also may have been affected.