Hundreds of people demonstrated on Saturday in the Tunisian capital against the government under the slogan "opposition is not a crime", calling for the release of jailed activists.

The rally in Tunis was called after the recent arrests of three opposition figures convicted of "conspiracy" against the state.

Tunisia emerged from the Arab Spring era of revolts as a democracy but, after Saied staged a sweeping power grab in 2021, rights groups have criticised a major rollback on freedoms.

Dozens of Saied's critics have been prosecuted or jailed, including on terrorism-related charges and under a law the president enacted in 2022 to prohibit "spreading false news".

Protesters held up portraits of several of them.

"Since the coup, things have changed completely. We've seen our freedoms taken away gradually, even though we did have a revolution," said Hager Chebbi, daughter of opposition figure Ahmed Nejib Chebbi, among those recently arrested.

"It's a descent into hell," she told AFP.

Amnesty International said the trial and Chebbi's arrest were part of the authorities' "blind and repressive escalation" in cracking down on dissenting voices.

"Fifteen years after the revolution, it is as if dictatorship has officially marked its return," Human Rights Watch's Middle East and North Africa spokesman Ahmed Benchemsi told AFP.