Protesters shouting anti-government slogans allegedly attacked banks and a police station during demonstrations in the city of Zahedan, in south-eastern Iran, after Friday prayers.

Police arrested at least 57 "rioters," provincial police chief Ahmad Taheri told the state news agency IRNA.

Unverified videos on social media showed thousands of protesters chanting "Death to the dictator," a reference to Supreme Leader Ayatollah Ali Khamenei, and "Death to Basijis," in reference to the Basij militia which has been widely used to crack down on recent protests.

The Islamic Republic has witnessed five weeks of demonstrations after the death of 22-year-old Jina Mahsa Amini. She died after being arrested by the regime's "morality police."

Hardliner wants tougher crackdown

Friday's demonstrations in Zahedan came three weeks after dozens were killed in "Bloody Friday" protests.

Amnesty International said security forces killed at least 66 people in a violent crackdown after Friday prayers in Zahedan on September 30.

Violence erupted in the city during protests that were triggered by anger over the reported rape of a teenage girl by a police commander in the region.

Her rape further fueled the public anger that was sparked by Amini's death in detention. 

The nationwide protests have turned into one of the boldest challenges to Iran's rulers since the 1979 revolution.

Protesters have called for the downfall of the Islamic Republic.

In Tehran, hardline cleric Ahmad Khatami called for tough measures against demonstrators across the country.

"The judiciary should deal with the rioters — who betrayed the nation and poured water into the enemy's watermill — in such a way that others don't again fancy to riot," he said during a Friday prayers sermon.

"They have told deceived kids if they stay in the streets for a week the regime will fall. Dream on," Khatami added.

Germany's warning for dual nationals

In a separate development on Friday, Germany issued a travel warningfor Iran, saying there was a real risk of being arbitrarily arrested and sentenced to long prison terms, above all for dual nationals.

Friday's announcement raised the warning level for Iran travel after Berlin strongly advised against it last month.

On Wednesday, an Iranian news agency said security forces had arrested 14 foreigners, including American, British and French citizens, for their involvement in the protests.

lo/sms (Reuters, AFP)