Reporters Without Borders (RSF) has condemned the arrest of "more than 20 international journalists" by Israeli forces during the interception of an international aid flotilla for Gaza between Wednesday and Thursday and demanded their "immediate release."

"Arresting journalists and preventing their work constitutes a serious violation of the right to inform and be informed. RSF condemns the illegal arrest of information professionals on board these ships to cover a humanitarian operation of unprecedented scale," said Martin Roux, head of RSF's crisis desk, in a statement released Thursday evening.

According to the French press freedom NGO, around twenty journalists were on board, including journalists from Spanish (the Telesur channel and the daily newspaper El País), Qatari (the Al-Jazeera channel), Italian (the public broadcaster RAI), Turkish (the public media TRT) and French (Émilien Urbach, from the daily newspaper L'Humanité).

The Global Sumud flotilla of 45 boats, including politicians and activists such as Sweden's Greta Thunberg, set off from Spain in September with the aim of breaking Israel's blockade of the war-torn Palestinian territory, which the UN says is suffering from famine.

On Wednesday evening, the Israeli Navy began intercepting the boats after warning the crews that they were entering waters over which Israel claims control.

More than 400 activists aboard 41 ships in the flotilla were arrested during an operation lasting approximately 12 hours, an Israeli official said Thursday evening.

"The various editorial offices have not received any news from their journalists," RSF said.

Without contact with Emilien Urbach since "Thursday at 3 a.m.", the SNJ-CGT union of Humanity denounced in a press release on Friday "an unacceptable obstacle to the free exercise of the profession of journalist."

"Like the rest of the media professionals arrested by Israeli forces, the journalist (Emilien Urbach) is likely to be held at the port of Ashdod, halfway between Tel Aviv and the Gaza Strip," RSF added in its statement.

Since the beginning of the war, the international press has not been allowed to work freely in the Palestinian territory.

Only a select few media outlets entered the area, embarked with the Israeli army, their reports being subject to strict military censorship.

RSF has counted more than 210 journalists killed since the start of Israeli military operations in Gaza, in retaliation for the deadly attack of October 7, 2023 by the Islamist movement Hamas.