The retailer says shoppers may have had their personal information stolen and it could be used for various consumer scams.
The breach of Canadian data was announced earlier this week when Target emailed some customers saying it believed their information may have been taken if they visited U.S. Target stores between Nov. 27 and Dec. 15.
However, the message was sent to at least some Target Canada customers who weren't in the United States over the affected period.
Target (NYSE:TGT) says an investigation found the personal information could have included the names, addresses, emails and phone numbers of some Canadians.
"This is generally publicly available information, so the primary risk is increased exposure to consumer scams, such as phishing, web scams and social engineering," the company said in an email to its customers.
Unlike affected U.S. customers, who had payment data from their debit and credit cards taken, the Canadian information is limited to contact information, the company said.
Canadian stores were not affected by the theft, it added.
"Because we value you as a guest and your trust is important to us, Target is offering you one year of free credit monitoring," the company said in an email to its customers.
The service is being offered through Atlanta-based credit monitoring agency Equifax.
Customers who opt for the free year of service will receive a credit report, round-the-clock monitoring of unusual activity, quarterly credit score updates and up to $25,000 in identity theft insurance.
The security breach is believed to have involved 40 million credit and debit card accounts and the personal information of 70 million customers.
The number of Canadians affected is estimated to be "well under'' one per cent of the total, which represents less than 700,000 customers, Target Canada spokeswoman Lisa Gison said earlier in the week.
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