Iranians defied a warning from the judiciary and took to the streets for a 10th consecutive night Sunday to protest the death of young Kurdish woman Mahsa Amini in morality police custody.
Echoing an earlier warning by President Ebrahim Raisi, judiciary chief Gholamhossein Mohseni Ejei on Sunday "emphasised the need for decisive action without leniency" against the core instigators of the "riots", the judiciary's Mizan Online website said.
Iran's largest protests in almost three years have seen security forces fire live rounds and bird shot, rights groups charge, while protesters have hurled rocks, torched police cars and set ablaze state buildings.
Oslo-based Iran Human Rights (IHR) on Sunday evening said the death toll was at least 57, but noted that ongoing internet blackouts made it increasingly difficult to confirm fatalities in a context where the women-led protests have spread to scores of cities.
Hundreds of demonstrators, reformist activists and journalists have been arrested during the mostly night-time demonstrations since unrest first broke out after Amini's death was announced on September 16.
Amini, whose Kurdish first name was Jhina, was detained three days before that for allegedly breaching rules mandating tightly-fitted hijab head coverings and which ban, among other things, ripped jeans and brightly coloured clothes.
Images circulated by IHR showed protesters on the streets of Tehran, shouting "death to the dictator", purportedly after nightfall on Sunday.
- 'Rolling blackouts' -
Among the protesters were women who burnt their hijabs and cut off their hair. Some danced near large bonfires to the applause of crowds that have chanted "zan, zendegi, azadi" or "woman, life, freedom".
Video of demonstrations on Saturday, verified by AFP, showed students ripping down a picture of supreme leader Ayatollah Ali Khamenei outside a university in the northern province of Mazandaran.
Web monitor NetBlocks noted "rolling blackouts" and "widespread internet platform restrictions" on Sunday, with WhatsApp, Instagram and Skype already blocked.
This followed older bans on Facebook, Twitter, TikTok and Telegram.
Protests abroad in solidarity with Iranian women have been held in Athens, Berlin, Brussels, Istanbul, Madrid, New York and other cities.
In Paris and London on Sunday, police clashed with demonstrators trying to reach Iran's embassies. French officers fired tear gas. In London, 12 people were arrested and five officers seriously hurt, police there said.
EU foreign policy chief Josep Borrell deplored the Iranian security forces' response to the unrest as "disproportionate... unjustifiable and unacceptable".
Iran, which has been hit with tough economic sanctions over its nuclear programme, has blamed "foreign plots" for the unrest.
Iran's foreign ministry said Sunday it had summoned Britain's ambassador over what it described as an "invitation to riots" by Farsi-speaking media based in London.
The ministry also called in Norway's envoy over "unconstructive comments" made by his country's parliamentary speaker.
Foreign ministry spokesman Hossein Amir-Abdollahian criticised "the US interventionist approach in the affairs of Iran... including its provocative actions in supporting the rioters".
- Pro-government rallies -
Iran has also organised large rallies in defence of the hijab and conservative values.
At the main pro-government event held Sunday in central Tehran's Enghelab (Revolution) Square, demonstrators voiced support for mandatory hijab laws.
"Martyrs died so that this hijab will be on our head," said demonstrator Nafiseh, 28, adding that she opposed making the wearing of the head covering voluntary.
Another demonstrator, 21-year-old student Atyieh, called for "strong action against the people who are leading" the protests.
The main reformist group inside Iran, the Union of Islamic Iran People's Party, however, has called for the repeal of the mandatory dress code.
IHR reported on Sunday that an umbrella of Iranian teachers' unions were calling on teachers and students to boycott classes on Monday and Wednesday in support of the protests.
Iranian authorities have yet to state the cause of death of Amini, who activists say died as a result of a blow to the head.
Interior Minister Ahmad Vahidi has said Amini was not beaten and that "we must wait for the final opinion of the medical examiner".