Paris (France) (AFP) - Protests in Iran have subsided after a crackdown that has killed thousands under an internet blackout, monitors said Friday, a week after the start of the largest demonstrations in years challenging the country’s theocratic system.

The son of Iran’s late shah, however, said he was confident the Islamic republic would fall and called for intervention, though the threat of new military action by the United States against Iran has appeared to have receded for the time being.

Protests sparked by economic grievances started with a shutdown in the Tehran bazaar on December 28 but turned into a mass movement demanding the removal of the clerical system that has ruled Iran since the 1979 revolution.

People started pouring into the streets in big cities from January 8 but authorities immediately enforced a shutdown of the internet that has lasted over a week and activists say is aimed at masking the scale of the crackdown.

The “brutal” repression has “likely suppressed the protest movement for now”, said the US-based Institute for the Study of War, which has monitored the protest activity.

But it added: “The regime’s widespread mobilisation of security forces is unsustainable, however, which makes it possible that protests could resume.”

Reza Pahlavi, the son of Iran’s late shah, told a news conference in Washington that “The Islamic republic will fall – not if, but when.”

“I will return to Iran,” he said.

Norway-based rights group Iran Human Rights (IHR) says 3,428 protesters have been verified to have been killed by security forces, but warns the actual toll could be several times higher.

Other estimates place the death toll at more than 5,000 – and possibly as high as 20,000 – with the internet blackout severely hampering independent verification, IHR said.

The opposition Iran International channel based outside the country has said at least 12,000 people were killed during the protests, citing senior government and security sources.

IHR director Mahmood Amiry-Moghaddam cited “horrifying eyewitness accounts” received by IHR of “protesters being shot dead while trying to flee, the use of military-grade weapons and the street execution of wounded protesters”.

- ‘Give Iran a chance’ -

Monitor Netblocks said that the “total internet blackout” in Iran had now lasted over 180 hours, longer than a similar measure that was imposed during 2019 protests.

Amnesty International said this was being backed up by the use of heavily armed patrols and checkpoints to crush “the nationwide popular uprising in Iran” with security forces visible in the streets.

Trump, who backed and joined Israel’s 12-day war against Iran in June, had not ruled out new military action against Tehran and made clear he was keeping a close eye on if any protesters were executed.

But a senior Saudi official told AFP on Thursday that Saudi Arabia, Qatar and Oman led “a long, frantic, diplomatic last-minute effort to convince President Trump to give Iran a chance to show good intention”.

While Washington appeared to have stepped back, the White House said Thursday that “all options remain on the table for the president”.

Attention had focused on the fate of a single protester, Erfan Soltani, a 26-year-old who rights activists and Washington said was set to be executed as early as Wednesday.

The Iranian judiciary confirmed Soltani was under arrest but said he had not been sentenced to death and his charges meant he did not risk capital punishment.

Rights groups have estimated up to 20,000 people have been arrested. Security officials cited by the Tasnim news agency on Friday said around 3,000 people were arrested.

- ‘All Iranians united’ -

The US Treasury on Thursday announced new sanctions targeting Iranian officials including Ali Larijani, secretary of Iran’s Supreme Council for National Security.

Russian President Vladimir Putin meanwhile held telephone talks with Iranian President Masoud Pezeshkian in what the Kremlin described as “efforts to facilitate de-escalation”.

Despite the internet shutdown, new videos from the height of the protests, with locations verified by AFP, showed bodies lined up in the Kahrizak morgue south of Tehran, as distraught relatives searched for loved ones.

At the UN Security Council in New York, Iranian-American journalist Masih Alinejad, invited to address the body by Washington, said “all Iranians are united” against the clerical system in Iran.

Iran’s representative at the meeting Gholamhossein Darzi accused Washington of “exploitation of peaceful protests for geopolitical purposes.”