BANGKOK (AFP) - Huddled around a table at a university canteen, six Thai students draft a newsletter celebrating democracy - a meeting that would have barely attracted a glance two months ago, but could now land them in jail.

They are part of a small but growing troop of undergraduates uniting in Bangkok to resist the curtailment of civil liberties under military rule.

"We should write about what isn't being reported," says Achara, a 24-year-old languages student spurred into action by the junta's censorship of domestic media.

Democratic rights. Students and the coup. The legality of the takeover. Just some of the ideas she lists in a notepad whose cover reads "Big things often have small beginnings".

These small and sporadic acts of resistance by students - from launching alternative publications to group readings of George Orwell's anti-authoritarian novel "Nineteen Eighty-Four" - are among the few public expressions against the takeover.

That is because even a typical campus debate on a newsletter carries a huge risk in post-coup Thailand, where the line between what the junta deems lawful and illegal is increasingly blurry.

Paradorn, a 20-year-old political sciences student, was arrested last month for handing out sandwiches after police thwarted a picnic rally.

"I've seen authoritarian rule in Thailand before. But I was shocked that 350 officers turned up," he says at a meeting of anti-coup friends at another Bangkok university.

- 'Freedom taken' -

Despite agreeing to forsake further political activity and face trial at a no-appeal military court if he breaches the terms of his release - conditions other arrested students have also had to sign - Paradorn remains defiant.

"I wasn't arrested because I did something wrong... My rights and freedom have been taken away. I cannot accept a system that wants to destroy democracy." Two days before it seized power on May 22, the army banned political assemblies of more than five people. It has responded increasingly aggressively to any form of protest.

In June, police arrested a lone student reading "Nineteen Eighty-Four" and eating a sandwich, while others have been detained for displaying a three-finger salute from the "Hunger Games" films - symbols of defiance against the junta.

Social media has become another target, with police trawling for dissenting voices, and authorities have even offered citizens a financial reward if they submit evidence linking someone to anti-coup activity.

This crackdown on freedom of expression has forced students to become more innovative in their campaigns.

To avoid detection, they rely on encrypted mobile apps, secret Facebook groups and even fake identities to plan protests - changing meeting times and locations at the last minute.

"But it's getting more and more difficult... We have to wait for chances and opportunities," says Anapit, 20, who was intercepted by police in June before he even had a chance to demonstrate.

He is part of a loose collective of 30 students - backed by dozens of others on the sidelines - so closely monitored by the military that officers frequently call him directly to dissuade members from taking any action.

- High stakes -

These campaigners know the risks of protesting - scores of students were massacred by authorities during a political demonstration at Bangkok's Thammasat University in 1976 in what remains a dark and largely unacknowledged chapter in Thai history.

Yet they remain emboldened by the tradition of students fighting for democracy in the kingdom, which has seen 19 failed or successful coups since 1932.

"I'm willing to go to the military court, but it has to be worth it, for something big, a rally or something," Anapit says in a high-end mall near where he was detained.

Some of the students may be aligned on party lines, but he thinks the majority are just fighting for democratic freedoms they have never been able to take for granted in Thailand.

"It's not about Yellows versus Reds," he says, referring to the colours of rival political movements that have fractured the country for years.

The military claims it was forced to seize power after nearly seven months of political street protests which left 28 people dead and hundreds of others wounded.

But critics accuse the junta of using the unrest as a pretext to curb the political dominance of fugitive former premier Thaksin Shinawatra and his allies, who have won every election in more than a decade.

With no end in sight to the long-running crisis, Thai students are not prepared to watch their rights being eroded in silence.

Back in the canteen, a lively debate is under way on how the newsletter could target readers outside Bangkok, when Achara suddenly stops mid-sentence.

She is responding to a now familiar look on the face of her friend who thinks he has spotted a plain-clothes officer.

Luckily, it is a false alarm. "Keep talking," he says.

AFP has changed the names of those interviewed to protect their identities.