The University of Queensland has promised to take action after a pro-Hong Kong Lennon wall on its campus was torn down on Monday night by four masked men.

The colourful protest wall – similar to those around Hong Kong and the rest of the world – had attracted hundreds of notes calling for democracy and solidarity with Hong Kong, and opposing the totalitarianism of the Chinese government.

Two weeks ago pro-Beijing government protesters clashed violently with Hong Kong international students on the university’s Brisbane campus, punching and shoving.

Lennon walls, inspired by a wall in Prague that 1980s activists decorated with Beatles quotes, have become a popular form of protest against Hong Kong’s controversial extradition bill. The first Hong Kong Lennon wall was created during 2014’s umbrella movement. They have spread widely this year, including to Australian campuses.

At UQ, Hong Kong students created the colourful wall on Friday, with messages such as: “Stand with Hong Kong. Protect freedom of speech.”

Jack Yiu, a Hong Kong international student who had been involved in campus protests, told Guardian Australia that masked people had torn down the posters.

“We had someone see it around 11pm and it was fine,” he said. “We got reports around midnight that four guys in masks came and just tore everything apart. We have them on the footage. The CCTV got them. We are trying to figure out who did that – even whether they are students or not.”

A UQ spokeswoman said if any of the men were identified and associated with the university, it would take appropriate action It would also increase security around the wall.

“The university does not condone any actions that prevent free speech, including the targeting of the Lennon wall in the student union complex overnight,” she said. “The UQ Union has CCTV footage of their premises and has provided it to the university.”

Police had been notified and security patrols would be stepped up.

Yiu said up to 100 students had contributed messages. “We kept fixing it and putting more stuff on it. It became bigger and prettier – everyone’s effort and time.

“Everyone is free to put up a sticky note. Even some Chinese students put up some counter-opinions on it, and we are fine with that. Everyone is free to express their opinions – just don’t tear anything down. You’re not supposed to silence us, or get rid of debate.”

By Tuesday students had returned to re-decorate the wall, and Yiu said the men’s action was not likely to dampen their protests. “We won’t stand down because of violence and those actions against us. We’re just expressing our support to Hong Kong about democracy and freedom of speech.”

Please RT: Over night, masked CCP thugs tore down a large pro-Hong Kong Lennon Wall at UQ. Pro-CCP wall is of course still intact. No statement from the university. I am utterly shocked and appalled. What is happening to us? pic.twitter.com/cFaQ1rQ5Ya — Drew Pavlou (@DrewPavlou) August 5, 2019

Tension has also flared around other Lennon walls on Australian university campuses.

At the University of Tasmania, a staff member had to intervene on Tuesday to stop a student tearing down pro-Hong Kong posters, according to the ABC. A similar incident took place last week.

Here are some of my images of the pro-democracy posters at the Sandy Bay @UTAS_ campus. Staff and security intervened this afternoon to stop the removal of the display #HongKong @togatus_ pic.twitter.com/2sTQgiBlAR — Monte Bovill (@MonteBovill) August 6, 2019

At the Australian National University in Canberra, students were told in an email from the acting vice-chancellor that Hong Kong and Chinese students had agreed to split a wall in two and limit their posters to separate sides.

The acting vice-chancellor, Prof Mike Calford, said students from both sides had agreed to regulate the content of their postings “to avoid offensive, irrelevant and disrespectful material” and to put up signs encouraging others to behave the same way.