Activewear brand Lululemon is in hot water in China after a promotional event held on the Great Wall appeared to mistakenly feature a Japanese drum – setting off an online furor.

The consumer backlash, which prompted Lululemon to issue an apology and scrub its campaign, is the latest example of how quickly Western brands can come unstuck in a country where nationalism has surged under strongman leader Xi Jinping.

It began with a yoga festival organised by Lululemon on the Great Wall on May 30, according to Chinese state-run tabloid Global Times.

One prominent guest was Chinese actor Zhu Yilong, known for his roles in popular movies and television shows like “Guardian,” “The Story of Minglan” and “Lighting Up the Stars.” At the festival, he joined a drum troupe in performing on what was initially described as a traditional Chinese drum, Global Times reported.

But the provenance of the drum soon came into question – with social media users and musicians claiming it appeared to resemble a Japanese Taiko drum instead.

The drum drama went viral this past week, garnering more than 50 million views on Chinese social media site Weibo by Monday, Global Times reported. Zhu’s studio weighed in on Tuesday, urging Lululemon to “verify the entire process and to review, analyze, and follow up on the matter.”

Lululemon responded to the controversy on Tuesday, saying the event had been “intended to unwaveringly pay tribute to Chinese culture.”

“Due to limitations in our professional knowledge, we were unable to fully identify potential controversies initially, and we fully recognise that we should be more cautious and thorough in the early planning and review process of the drum performances,” it said, apologising to both Zhu and the public.

It vowed to “learn profound lessons” and to adopt “a more rigorous attitude” in future events.

-CNN