SEOUL - K-pop girl group Twice were named the ambassadors of Indonesian beauty brand Scarlett Whitening last week, but not everyone is happy about it.

There have been calls worldwide, not just in Indonesia, for Twice's management agency, JYP Entertainment, to end the endorsement deal.

In an e-mail template which gained traction on Twitter over the weekend, their fans, known as Once, wrote: "As Twice's fans, we find it important that we're all respected regardless of our race/ethnicity. We find it unethical that Twice are promoting a brand with skin whitening products, knowing that they have fans with darker skin complexions."

Fans have also been vocal on Twitter, explaining why they were offended.

"Whitening products really give the impression that to be perceived as beautiful, you need to look 'white' and this is heavily influenced by Western/European culture," one wrote.

Another tweeted: "Releasing an English single to attract more of an international audience which is filled with people of all races and ethnicities and then promoting a skin whitening brand two weeks after the English single... it's just so sad."

The nine-member group released their first English single, The Feels, on Oct 1.

While JYP Entertainment did not issue a statement on the outcry, it has deleted its initial tweet announcing the endorsement.