Universities have become the latest battleground over freedoms in Hong Kong as a ban on signs on campuses advocating independence from China sparks fresh fears that the city's liberties are under threat.
As term kicked off earlier this month, posters and banners calling for semi-autonomous Hong Kong to split from the mainland were plastered on walls and bulletin boards after a tense summer that saw pro-democracy lawmakers ousted and leading activists jailed.
Independence calls grew out of the failure of mass Umbrella Movement rallies in 2014 to win democratic reform for Hong Kong and have been fanned by growing concerns that Beijing is tightening its grip on the city.
The nascent independence movement has incensed China and local officials have also railed against activists.
When university chiefs penned a joint statement last week describing pro-independence banners as an abuse of free speech, angry students accused them of kowtowing to Beijing and censoring legitimate political debate.
"Freedom of expression is not absolute," the statement said, casting independence as contravening the city's mini-constitution, the Basic Law.
University authorities also ordered students to immediately take down banners that violated school policies.
Student unions questioned how putting a political opinion went against the Basic Law, which guarantees freedom of speech.
"Universities are supposed to be the last bastions to defend these values, but instead they became the first ones to try to control (us)," Justin Au, president of the student union at the Chinese University of Hong Kong, told AFP.
"We find it very bizarre," he added, saying he believed the move came under pressure from the government.
Student anger was also exacerbated when a pro-Beijing legislator called for the murder of independence advocates at a public rally last week, with little public chastisement from authorities.
"It shows the powerful may have more freedom of speech than ordinary citizens," said Thomas Lee, secretary at the CUHK student union.
- 'Like 1984' -
But there has also been pushback from mainland students on campuses against the independence signs, with rival posters now slapped up on the universities' public "democracy walls" where people can have their say.
Several mainland students interviewed by AFP at CUHK largely condemned the pro-independence banner that had gone up there, saying that it made them uncomfortable as Chinese people or that it was simply naive or "stupid".
"It's unrealistic, they don't understand the country," said one student who gave her name as Chloe.
"I think the banner is a bit stupid," added a student from Guangzhou who provided his surname as Kwan.
"The freest people are those who follow the rules. Those who don't will feel oppressed everywhere."
City leader Carrie Lam has said there is "no room for discussion" of a split from China and what was happening at the universities required "immediate action".
Analysts say Hong Kong's hard line on independence reflects Beijing's zero tolerance.
"It is the one thing they fear most because it anticipates the break-up of a unified China," said Suzanne Pepper, an honorary fellow at CUHK.
"I think Beijing would rather destroy Hong Kong than allow that advocacy to take root here."
In a speech in Hong Kong in July, China's president Xi Jinping warned against challenges to Beijing's sovereignty, saying it crossed a "red line".
There have already been fears over interference in Hong Kong's education system and some teachers have said they feel under increasing pressure to self-censor.
There was also controversy when a pro-Beijing figure was chosen to lead the governing body at the University of Hong Kong after a popular liberal scholar was passed over for a senior post.
CUHK's Au says whether or not people are in favour of independence, it should be discussed as part of a debate on the future of Hong Kong after 2047, when the 50-year agreement made on its handover from Britain to China guaranteeing its freedoms and way of life expires.
While he said he believes that free speech comes with responsibilities, such as not advocating hate speech or posing immediate dangers to others, he says the restrictions now being imposed on students are distorting the true meaning of freedom of expression and trying to redefine it in a way more palatable to Chinese authorities.
"Like 1984's 'Big brother is watching you' -- this is not the kind of society we want to become," added CUHK's Lee.
"If we don't come out to defend (our rights) they will gradually disappear."