Fearing a revival of the unrest that rocked the Islamic Republic, Iran’s clerical rulers have increased their clamp down on dissent aimed at deterring any gatherings on Mahsa Amini’s death anniversary on Sept. 16.

“A group of security forces went to Amini’s uncle Safa Aeli’s home yesterday … searched his car and house without having a court order and then arrested him … they also confiscated some documents like his passport,” said the source.

“Prior to his arrest, Aeli was followed by security forces for a week … The family does not know where he has been taken.”

Iran’s judiciary did not respond to Reuters request for comment.

The months-long anti-government protests spiralled into the biggest show of opposition to Iran’s authorities in years, with many calling for the end of more than four decades of Islamic clerical rule.

Over 500 people – including 71 minors – were killed, hundreds wounded and thousands arrested during the unrest that was violently quelled by Iran’s security forces, Rights groups said.

France-based Kurdistan Human Rights Network (KHRN) said on Tuesday that the security forces have mounted pressure on the family members of protesters killed in the unrest by summoning, threatening or arresting them in recent weeks.

“The families have been threatened to avoid calling for any gatherings to mark Amini’s anniversary,” it said.

In a report last month, Amnesty International said Iranian authorities “have been subjecting victims’ families to arbitrary arrest and detention, imposing cruel restrictions on peaceful gatherings at grave sites, and destroying victims’ gravestones.”

Many journalists, lawyers, activists, students, academics, ethnic minorities, artists, public figures and family members of protesters killed in the unrest have been arrested, summoned, threatened or fired in the past few weeks, according to Rights groups.

Iran’s Etemad daily reported in August that the lawyer for Amini’s family also faces charges of “propaganda against the system”. If convicted, Saleh Nikbakht faces a jail sentence between one and three years.

Authorities have accused Islamic Iran’s arch-enemies the United States and Israel and their local agents of being behind the unrest to destabilise the country.

Iranian officials have said that many members of the security forces have been killed by “rioters and thugs backed by foreign foes”.

(Writing by Parisa Hafezi; Editing by Alexandra Hudson)