According to official figures, 17 people have been killed in the largest protests in Iran in almost three years.
The Iran Human Rights (IHR) organization based in Oslo even said on Thursday that at least 31 civilians had died as a result of the security forces' actions against the protests since the death of a woman arrested by the vice squad.
The authorities further restricted access to the Internet and blocked the online networks Whatsapp and Instagram.
Iranian state television reported that 17 people had died since the protests broke out on Friday last week.
According to the Tasnim news agency, five members of the security forces were among the dead.
The death of 22-year-old Mahsa Amini had sparked a nationwide wave of outrage and protests.
The young woman was arrested by the vice squad in the capital Tehran a week ago because she was apparently not wearing the Islamic headscarf in accordance with strict regulations.
Amini collapsed at the police station under mysterious circumstances and was pronounced dead at the hospital three days later.
Police say she had a heart attack.
According to human rights activists, Amini suffered a fatal blow to the head.
Protests in at least 15 cities
Iranian President Ebrahim Raisi referred to the official autopsy result on Thursday on the fringes of the UN general debate in front of journalists in New York, but confirmed that investigations would be started.
He personally assured Amini's family of this.
According to Iranian state media, there have been protests in around 15 Iranian cities since the young woman's death, and human rights activists speak of more than 30 cities.
Videos posted online show protesters taking off their headscarves and burning them or cutting their hair in front of a cheering crowd.
In Isfahan, protesters tore up a banner with a picture of Iran's spiritual leader, Ayatollah Ali Khamenei.
With Instagram and Whatsapp, access to the two most-used apps in Iran has now been blocked.
In recent years, the Iranian authorities have blocked many other platforms such as Facebook, Telegram, Tiktok, Twitter and YouTube.
Internet connections have also slowed significantly since the protests began.
The beginning of something bigger?
IHR director Mahmud Amiri Moghaddam told AFP the protests could "perhaps be the beginning of a big change" in Iran.
"We have been following the human rights situation and the demonstrations in Iran for 15 years and I have never seen people so angry," said the human rights activist.
Federal Foreign Minister Annalena Baerbock (Greens) announced on Thursday in New York that she would bring the violent crackdown on the demonstrators to the UN Human Rights Council.
The "brutal attack on the courageous women in Iran" is "also an attack on humanity," said Baerbock on the fringes of the general debate.
The human rights organization Amnesty International called on the heads of state and government present in New York to "support an independent international investigation and accountability mechanism to address widespread impunity in Iran".
The US imposed sanctions on the Iranian vice squad and several security officials.
Meanwhile, star journalist Christiane Amanpour reported on Twitter that an adviser to the Iranian President asked her in New York on Wednesday to wear a headscarf for an interview with Raisi.
She refused and pointed out that no Iranian head of state had ever asked for this in an interview outside of Iran.
The interview was then canceled.