Law enforcement and security officers have prevented families of prisoners who have been handed death sentences from demonstrating in front of Iran's judiciary headquarters in Tehran.
The September 12 gathering was to be the sixth consecutive day of such protests, which have been held under the slogan "No to execution."
There was no official report on people being detained and whether they have been released, but most of the attendees were women and children, eyewitnesses said.
In videos of the protests posted on social media, police officers can be seen dispersing the demonstrators, who identified themselves as relatives of those on death row, arresting some of them.
According to one foreign-based Iranian rights group, at least 18 prisoners sentenced to death have been transferred to solitary confinement from the Karaj, Minab, and Gohardasht central prisons to different parts of Iran.
Judicial officials have yet to respond to the demands of the protesters.
Many protest rallies have been held in Iran in recent years, but a rally to oppose the death sentence is a rare act of defiance.
As of September 12, at least 410 executions had been recorded in Iran this year, according to the Iran Human Rights Organization.
Some human rights sources, including the Human Rights Activists News Agency, say that more than 85 percent of executions in Iran are carried out "in secret and without official and public information."
The rise in the number of executions began in September 2021 after Ebrahim Raisi, a former head of the judiciary, became president and former Intelligence Minister Gholamhossein Mohseni-Ejei took over the judiciary.
Activists say that Iran is in the throes of a major crackdown as protests continue over living conditions in a severe economic crisis.