Department store Tokyu Hands Inc. disclosed Friday that information on 861 customers was stolen after its online store for handmade products was accessed without authorization.

The stolen data included credit card numbers for 529 customers, and more than 10 are already likely to have been used for illegal purchases, the operator of stores for upscale home improvement and lifestyle products said.

The compromised customers had made purchases from the Hands Gallery Market between Jan. 4 and Sept. 9.

A credit card company tipped off the chain about the potential data leak on Sept. 9, Tokyu Hands said. The financial damage remains unknown.

Tokyu Hands suspended the Hands Gallery Market and reported the incident to the police on Thursday, and said it will notify and compensate every customer for the cost of replacing the credit cards.