(REUTERS) — U.S. retailer Gap apologized on Monday for selling a T-shirt which it said had an incorrect map of China, adding it would implement “rigorous reviews” to prevent a repeat mistake.

The apology came after a person posted pictures of the T-shirt on Chinese social media network Weibo, saying that Chinese territories, including south Tibet, the island of Taiwan and the South China Sea, were omitted from the map. The user said the photo of the T-shirt was taken at an outlet store in Canada.

“Gap Inc. respects the sovereignty and territorial integrity of China. We’ve learned that a Gap brand T-shirt sold in some overseas markets failed to reflect the correct map of China. We sincerely apologize for this unintentional error,” it said in a statement posted on its Weibo account on Monday evening.

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