Changes to the charter of one of China’s top universities, including dropping the phrase “freedom of thought” and the inclusion of a pledge to follow the Communist party’s leadership, has sparked fierce debate and a rare act of student defiance.

The changes to the charter of Fudan University in Shanghai, considered one of China’s more liberal institutions, emerged on Tuesday when the education ministry said it had approved the revisions for three universities.

Within hours, the Fudan amendments were trending on Weibo with one hashtag viewed more than a million times.

“If I may dare to ask those who initiated the amendment of the Fudan University charter, how do you expect our generation of Fudan people to face our ancestors?” said one user of the social media site.

That post, and many similar posts questioning the changes, in particular the removal of “freedom of thought”, were deleted by Wednesday afternoon although the issue was still being discussed in private WeChat groups.

Since President Xi Jinping came to power in 2012, China has tightened controls on the internet and various aspects of civil society in a campaign that has seen increased censorship and shrinking space for protests, including on campuses.

The revisions to the university charters come as Beijing grapples with anti-government protests in Hong Kong which have involved many students.

A video circulating on Twitter on Wednesday showed a group of Fudan students singing their college anthem, which includes the phrase “freedom of thought”, during their lunch break. Students at the university confirmed to Reuters that the event had taken place.

Telephone calls to Fudan’s press department went unanswered and the Ministry of Education did not immediately respond to a faxed request for comment.

Student protests have been rare in China since the crackdown of a student pro-democracy campaign in Tiananmen Square in Beijing in 1989.

The new charter said the university would “weaponise the minds of teachers and students using Xi Jinping’s socialism ideology with characteristics of China in the new era”.

Fudan is ranked 109 globally in the Times Higher Education’s 2020 world university rankings.

The two other universities that made changes to their charters were Shaanxi Normal and Nanjing, according to documents published by the Ministry of Education that showed it had approved the changes on 2 December.

Their revised charters similarly included references to strengthening the leadership of the Communist party at the universities.