Iranian state media say seven people were killed and 10 injured in a November 16 "terrorist attack" in the southwestern Iranian city of Izeh.
Iran's state news agencies described the incident as a terrorist attack while referring to the dead as martyrs. State media reported that a 9-year-old boy, identified as Kian Pirfalak, was among those killed.
But activists and relatives of Pirfalak blamed security forces for his killing, which occurred as protests over the September 16 death in custody of Mahsa Amini intensified on the third anniversary of the November 2019 bloody unrest over fuel price hikes.
The opposition activist collective 1500tasvir reported that a large number of protesters were killed in Izeh on November 16 while blaming the Islamic republic's security forces for the killings.
In a video showing Pirfalak's body published online, one of his relatives said he was shot by the "security forces of the Islamic republic" and killed while he was riding in a car with his father.
Meanwhile, the official government news agency IRNA published a statement saying the extremist group Islamic State (IS) had claimed responsibility for the attack in Izeh.
However, the BBC monitoring service said some supporters of IS called the group's claim of responsibility fake.
Later, the state news agency IRNA removed the statement without offering any explanation.
The opponents of the Islamic republic accuse the government of attempting to divert public opinion from the protests.
Officials have blamed Western governments and intelligence services for the unrest, which was sparked by the death of Amini while she was in police custody for an alleged dress-code violation relating to how she was wearing a head scarf.
They have not presented any evidence to back up their claims.
Authorities have met the unrest with a harsh crackdown that the Oslo-based group Iran Human Rights says has killed at least 300 people, including 40 children.