PARIS, France -- Iran's protest crackdown has helped push the number of journalists imprisoned worldwide to a record high of 533 in 2022, according to a report by Reporters Without Borders (RSF) published Wednesday.

The figure is up from 488 in 2021, already a record, according to the France-based NGO.

More than half are detained in just five countries: China, which remains "the world's biggest jailer of journalists" with 110, followed by Myanmar (62), Iran (47), Vietnam (39) and Belarus (31).

"Dictatorial and authoritarian regimes are filling their prisons faster than ever by jailing journalists," said Christophe Deloire, RSF Secretary-General, in a statement.

"This new record in the number of detained journalists confirms the pressing and urgent need to resist these unscrupulous governments and to extend our active solidarity to all those who embody the ideal of journalistic freedom, independence and pluralism."

Iran is the only country that was not part of the list last year, said RSF, which has been publishing the annual tally since 1995.

It said Iran had locked up an "unprecedented" 34 media professionals since protests broke out in September over the death in custody of 22-year-old Mahsa Amini, who was arrested for breaching the country's strict dress code.

'Deliberately targeted'

The number of women journalists in prison is also at an all-time high worldwide, rising from 60 to 78 since 2021, largely due to greater numbers entering the profession.

It highlighted the cases of Iranians Nilufar Hamedi and Elahe Mohammadi -- among 15 female journalists arrested during the protests -- who drew attention to the death of Amini and now face a potential death penalty.

It is "indicative of the Iranian authorities' desire to systematically reduce women to silence," RSF said.

The NGO awarded its Prize for Courage on Monday to one of their number, Narges Mohammadi, who has been repeatedly imprisoned over the past decade.

Three quarters of jailed journalists are concentrated in Asia and the Middle East, RSF, while noting a sharp increase in media repression in Russia since its invasion of Ukraine.

The number of journalists killed has also risen -- to 57 -- due particularly to the war in Ukraine, up from "historic lows" of 48 and 50 in the last two years, respectively.

Eight journalists have been killed reporting on the war, five of them from non-combatant countries.

RSF said nearly 80 percent of media professionals killed around the world in 2022 were "deliberately targeted in connection with their work or the stories they were covering", such as organised crime and corruption cases.