TikTok has apologised for blocking a US teenager from the Chinese-owned video sharing platform after she posted a video highlighting Beijing’s treatment of Muslims in Xinjiang.

A spokesman for the platform on Thursday blamed a “human moderation error” for the removal of a video by 17-year-old Feroza Aziz disguised as a makeup tutorial to avoid being censored.

In the short clip, Aziz curls her eyelashes while calling on viewers to “spread awareness” of what is happening in Xinjiang, where the Chinese government has been accused of sending at least 1 million Uighurs and other minorities to internment camps.

The video was viewed more than 1.5 million times but Aziz was blocked from posting any more videos.

In a statement acknowledging the “significant interest and confusion” in Aziz’s case, Eric Han, head of safety at TikTok US, said: “Due to a human moderation error, the viral video … was removed. It’s important to clarify that nothing in our community guidelines precludes content such as this video, and it should not have been removed.”

Han said the company had previously banned an account by Aziz after she posted a satirical video about the prospect of marrying Osama bin Laden. As part of “scheduled platform-wide enforcement”, her second account was suspended a few days after she posted her makeup tutorial.

“Our moderation approach of banning devices associated with a banned account is designed to protect against the spread of coordinated malicious behaviour – and it’s clear that this was not the intent here,” Han said, adding that the company had contacted Aziz to tell her that her account had been reinstated.

Han said the company was reviewing the “procedural breakdown” in this incident and would be releasing a “transparency report” as well as a fuller version of its community moderation guidelines.

Aziz posted on Twitter that her account had been unblocked but cast doubt on the company’s explanations. She wrote: “Do I believe they took it away because of a unrelated satirical video that was deleted on a previous deleted account of mine? Right after I finished posting a 3-part video about the Uighurs? No.”

Aziz’s video and accusations of censorship come at a time when the Chinese leadership is facing international condemnation for its policies in Xinjiang, which China defends as counter-terrorism measures.

Several recent high-profile leaks detailing the use of involuntary internment camps for “ideological education” have undermined Beijing’s claims that it only hosts “vocational training centres” that people attend willingly.

Owned by the Beijing-based technology company ByteDance, TikTok is one of few Chinese apps that have gained popularity outside of China. TikTok has said that it does not apply Chinese censorship rules on the international version of its app.

Uighurs within China and those overseas have previously used Douyin, the app’s domestic version, to communicate or raise awareness of the situation but those accounts appear to have been scrubbed from the platform.

Leaked moderation guidelines seen by the Guardian barred content related to certain world leaders, Tiananmen Square, Tibetan independence and Falun Gong.

It did not mention Xinjiang specifically, but barred “highly controversial topics, such as separatism, religion sects conflicts, conflicts between ethnic groups, for instance exaggerating the Islamic sects conflicts”.