HONG KONG, July 7 - Chinese tech giant Tencent's WeChat social media platform has deleted dozens of LGBT accounts run by university students, saying some had broken rules on information on the internet, sparking fear of a crackdown on gay content online.

Members of several LGBT groups told Reuters that access to their accounts was blocked late on Tuesday and they later discovered that all of their content had been deleted.

"Many of us suffered at the same time," said the account manager of one group who declined to be identified due to the sensitivity of the issue.

"They censored us without any warning. All of us have been wiped out."

Attempts by Reuters to access some accounts were met with a notice from WeChat saying the groups "had violated regulations on the management of accounts offering public information service on the Chinese internet".

Other accounts did not show up in search results.

WeChat did not immediately respond to emailed questions.

While homosexuality, which was classified as a mental disorder until 2001, is legal in China, same sex marriage is not recognised. Social stigma and pressure still deter people from coming out.

This year, a court upheld a university's description of homosexuality as a "psychological disorder", ruling that it was not a factual error.

The LGBT community has repeatedly found itself falling foul of censors and the Cyberspace Administration of China recently pledged to clean up the internet to protect minors and crack down on social media groups deemed a "bad influence".

The Weibo social media platform, owned by Weibo Corp, has at times removed lesbian content and the online community board platform Zhihu has censored topics on gender and identity.

Last year, China's only pride festival was cancelled indefinitely after organisers cited concerns over staff safety.

"Authorities have been tightening the space available for LGBT advocacy and civil society generally. This is another turning of the screw,” said Darius Longarino, a senior fellow at Yale Law School's Paul Tsai's China Centre, who focuses on LGBT rights and gender equality.