A call had been made to protest outside the tourism ministry under the hashtag “#Sayebni” (“Let me go”) to demand the repeal of “retrograde” laws and the end of “the criminalisation of sexual freedom and discrimination against women”.
But activists said late Friday they had been told by the interior ministry that their demonstration had been banned.
“We had information that they were going to be targeted,” said ministry spokesman Khalifa Chibani told AFP.
The rally was banned “for their safety and to preserve public order”, he said, without elaborating.
The call to protest was made by the Association of Free Thinkers and relayed by the Shams association, which campaigns for the decriminalisation of homosexuality in Tunisia.
At the scheduled time of the protest, a dozen protesters, including one bearing a sign calling for a secular state, were moved on by policemen in plain clothes.
But there was a scramble when LGBT activists said they rejected the ban on demonstrations and two, including ex-Femen member Amina Sboui, tried to display a rainbow flag.
She and another activist were bundled into a police vehicle by the security forces.
Bouhdid Belhadi, general manager of LGBT web broadcaster “Shams Rad”, said he had had his arm twisted by police.
LGBT activists have emerged from the shadows since Tunisia’s 2011 uprising that launched the Arab Spring.
However, their position remains precarious for social reasons and legislation that punishes homosexual practices with three years in prison.