The Oslo-based Iran Human Rights has put the death toll at 92 since nationwide protests erupted last month.
At least 92 people have been killed in Iran since protests erupted over the death of Mahsa Amini last month after she was arrested by the so-called morality police.
This figure was revealed on Sunday by Iran Human Rights (IHR), a group that has been working to assess the death toll despite internet outages and blocks on online services.
London-based Amnesty International had earlier confirmed 53 deaths, while Iran's semi-official Fars news agency put the toll at "around 60" people last week.
Amini, 22, was pronounced dead on September 16 after she was detained for allegedly breaching rules requiring women to dress modestly.
Her death sparked Iran's biggest wave of popular unrest in almost three years. Clashes between Iranian protesters and security forces have rocked cities nationwide for 16 nights in a row after they first flared.
Trouble in the southeast
At the same time, Tehran is dealing with a security situation in the Sistan-Baluchestan province in the southeast.
The Oslo-based IHR said that 41 people were killed in clashes on Friday in the area, which borders Afghanistan and Pakistan.
The group said the protests were sparked by accusations that a police chief in the province's port city of Chabahar had raped a 15-year-old girl from the Sunni Baluch minority.
Tehran said five Revolutionary Guards members were killed in clashes on Friday in Zahedan, the capital of Sistan-Baluchestan province.
A Sunni Muslim preacher, Molavi Abdol Hamid, said the community was "inflamed" after the alleged rape of a teenage girl by a police officer in the province, in a post on the cleric's website on Wednesday.
IHR accused the security forces of the mainly Shia country of "bloodily repressing" the Zahedan protest.
Iran has accused outside forces of stoking the nationwide protests, especially its arch-enemy the United States and Washington's Western allies.