Around 300 people demonstrated in central Tunis Friday in solidarity with two journalists the Libyan branch of the Islamic State (IS) group claims it has executed.
"We are all Sofiene, we are all Nadhir," read placards held by the demonstrators, many of them young journalists, in reference to Sofiene Chourabi and Nadhir Ktari.
On Thursday, the IS branch in Libya issued a statement saying the pair, who went missing there in early September, had been executed because they had "sowed corruption in the land."
But echoing official statements, the head of the National Syndicate of Tunisian Journalists, Neji Bghouri, said the "news has still not been confirmed" and called on the government to uncover the truth.
"We chose to be journalists, and we know it is difficult. We have chosen freedom and we will carry on," he said.
Sami Ktari, father of one of the two, called on the authorities to "take the matter seriously."
Newly elected President Beji Caid Essebsi met the families of the two men Friday but has not made any public statement about the case.
But Foreign Minister Mongi Hamdi said the authorities are following the case "minute by minute."
Until such time as the claim of their deaths is confirmed, he said "we hope that they are false."
Hamdi expressed frustration Thursday over failed efforts to secure the two men's release, saying "we do not know who kidnapped them, why they kidnapped them or where they are."
Chourabi, an investigative journalist and blogger who was active during Tunisia's 2011 revolution, and Ktari, a photographer, went missing in the Ajdabiya district of eastern Libya on September 8.
Libya has been engulfed by chaos since the 2011 NATO-backed uprising that toppled and killed veteran dictator Moamer Kadhafi, with two rival governments and a host of militias now vying for territory.
IS has seized swathes of Iraq and Syria, declaring a "caliphate" and committing widespread atrocities, including the beheading of Western hostages.