After months of relative quiet, the issue of Hong Kong independence made a high-profile reappearance on Monday, as banners calling for a breakaway surfaced at Chinese University overnight ahead of the new academic year. School staff quickly removed the signs, leading the student union to accuse it of suppressing free discussion on the emotive topic. At least three large black banners bearing the words “Hong Kong independence” in Chinese and English festooned the school in Sha Tin, including a campus landmark and sculpture known as “The Beacon”, outside the library. Chinese University vice chancellor Professor Joseph Sung Jao-yiu said students were free to express their opinions but should not break the law. He did not say whether the stunt had been illegal, only noting: “As long as it is not illegal or disruptive to other people’s learning, we will not have too big of a reaction.” As long as it is not illegal or disruptive to other people’s learning, we will not have too big of a reaction Professor Joseph Sung, Chinese University He said the institution “is a place with freedom of speech”. But in a Facebook post, the student union said the signs’ quick removal showed that the school was suppressing talk on campus of separating the city from China. Au Tsz-ho, union president, said his group put a banner on the university’s Goddess of Democracy statue, to voice support for Hongkongers recently jailed over separate stormings of the government headquarters and the Legislative Council in 2014. He said the two cases would not be the only ones, adding that “the government’s oppression of people with opinions is getting more and more serious”. He said he was not sure who put up the other banners, but believed it was other Chinese University students. A Chinese University spokesman said the banners were hung at several spots on campus without any application for permission, and school staff removed them. “The school’s long-standing position is that it is absolutely not in favour of Hong Kong independence,” he said. Apart from the banners, dozens of posters featuring slogans suggesting the city break away from China were hung in different places, according to pictures uploaded to Facebook. The banners’ appearance on Monday morning came as first-year students and teaching staff attended an inauguration ceremony convened by Sung. The vice chancellor said after the ceremony that young people should care about society and fight for justice, but that they have to express their opinions in a rational and peaceful manner. Addressing the recent imprisonment of student leaders Alex Chow Yong-kang, Nathan Law Kwun-chung and Joshua Wong Chi-fung , over the government headquarters storming three years ago, Sung described judicial independence as a cornerstone of Hong Kong society. He urged Hongkongers to have confidence in it. Barrister Albert Luk Wai-hung said hanging the banners would not constitute any criminal offence as the school campus is a private space. Last month, the city’s top court rejected a final bid by two disqualified pro-independence lawmakers, Sixtus Baggio Leung Chung-hang and Yau Wai-ching, to be reinstated in the Legislative Council . The pair were unseated last year for their oath-taking , which included anti-China remarks . The saga prompted Beijing to issue an interpretation of the Basic Law , Hong Kong’s mini-constitution, and make such offences punishable by disqualification.