More than 300 Iranian journalists have demanded the release of two colleagues jailed for their coverage of Mahsa Amini, whose death in custody triggered protests posing one of the biggest challenges to ruling clerics in decades.

Their call came in a statement published by the Iranian Etemad and other newspapers on Sunday.

The arrests match an official narrative that Iran's arch-enemy the United States, Israel and other Western powers and their local agents are behind the unrest and are determined to destabilise the country.

At least 40 journalists have been detained in the past six weeks, according to rights groups, and the number is growing.

What began as outrage over Amini's death on Sept. 16 evolved into a popular revolt by people from all layers of society.

Students and women have played a prominent role, burning their veils as crowds call for the death of Supreme Leader Ayatollah Ali Khamenei and the toppling of the Islamic Republic, which has repressed any

dissent since the 1979 revolution.

There are no signs that a crackdown will defuse the fury, even after the feared head of Iran's powerful Revolutionary Guards warned protesters that Saturday would be their last day of taking to the streets, the harshest warning yet.

Analysts say Iran's leaders will manage to withstand the pressure but that the path to political change in the future could be irreversible.

CLERICS EXPECTED TO SURVIVE

The Revolutionary Guards and the volunteer militia Basij have crushed

dissent in the past - in 2009 protests lasted six months. No officials have publicly criticised the clerical establishment.

"Basijis are being insulted by the seditionists at universities and in the streets. So far, Basijis have shown restraint and they have been patient," the head of the Revolutionary Guards

in the Khorasan Junubi province, Brigadier General Mohammadreza Mahdavi, was quoted as saying by the state news agency IRNA.

"But it will get out of our control if the situation continues."

Videos on social media,

unverifiable by Reuters, showed students clashing with riot police and Basij forces in universities across the country, chanting "dishonoured Basij get lost".

Iran's Parliament Speaker, Mohammad Baqer Qalibaf, seemed to strike

a conciliatory tone, saying the difference between peaceful and violent protesters should be noted.