Women in Tehran, Iran, protest the death of Mahsa Amini in this Oct. 1, 2022. [AP Photo]

Iran is ratcheting up a crackdown ahead of the one-year anniversary of the death of Mahsa Amini, arresting prominent personalities, campaigners and relatives of those killed by security forces in protests last year, activists say.

The death in custody on September 16, 2022, of Amini, a 22-year-old Iranian Kurd who was arrested for allegedly violating the strict dress rules for women, sparked months of protests that included calls for an end to Iran's Islamic system.

Despite sporadic outbursts, the protests have largely subsided after a crackdown that saw thousands detained, according to the United Nations, and hundreds shot dead by security forces, according to activists.

But campaigners outside Iran say the authorities are acutely aware that the anniversary could spark more protests, and they say security forces have stepped up repression to prevent a repeat of the events of last autumn.

Those arrested this month have included the prominent singer Mehdi Yarrahi after he released a song urging women to remove their headscarves in defiance of the law.

Eleven women's rights activists were detained in Gilan province, one of the flashpoint areas for protests last year, according to the Human Rights Activists News Agency, or HRANA.

Meanwhile, Amnesty International has said families of those killed in the crackdown on the movement have been subjected to "arbitrary arrest and detention" in a bid to enforce "silence and impunity" over the fate of their loved ones.

"These arrests are a blatant attempt by Iranian authorities to instill fear within the population ahead of the upcoming anniversary [and] to deter more protests," Hadi Ghaemi, executive director of the New-York-based Center for Human Rights in Iran, or CHRI, told AFP.

Cruelty 'knows no bounds'

In a report, Amnesty said families of victims killed in the crackdown across the country have been subjected to abusive interrogations, arbitrary arrest and detention, and or unjust prosecution and sentencing in recent months.

"The cruelty of the Iranian authorities knows no bounds," said Diana Eltahawy, Amnesty's deputy regional director for the Middle East and North Africa, accusing the Iranian authorities of a "sinister attempt to cover up their crimes."

In a new example, security forces on Sunday arrested three family members, including the mother, of Hananeh Kia, a woman in her early 20s shot dead by security forces in September 2022 during the initial phase of the protests, HRANA and the Hengaw rights group said.

The CHRI said in just eight days this month, 21 family members of victims were either summoned to court or detained in Iran.

Roya Boroumand, executive director of the U.S.-based Abdorrahman Boroumand Center, said "victims' family members have been targeted pretty systematically."

"They have been arrested, summoned repeatedly and interrogated, or their houses are raided," she said, adding that pressure was being put on them not to post anything on social media, gather for commemorations, or speak out.

The protests broke taboos that have prevailed in the Islamic republic since the fall of the shah in 1979, with women taking off their headscarves and slogans chanted against Iran's supreme leader, Ayatollah Ali Khamenei, in street protests.

In a separate report, Amnesty has said Iran has renewed its crackdown against unveiled women, with stepped-up patrols backed by surveillance cameras that can even identify women inside their cars. Images shared on social media indicate some women, however, are continuing to show defiance.

'Killing machine'

Meanwhile, Norway-based Iran Human Rights says 486 people have been executed in Iran this year, with the use of capital punishment aimed at "creating fear in society and to prevent more protests."

While seven men have been executed in cases related to the protests, causing an international outcry, most of those hanged are convicted on drug and murder charges and are "low-cost victims of the Islamic republic's killing machine," it added.

According to the CHRI, Mashallah Karami, the father of executed protester Mohammad Mehdi Karami, who was hanged in January, was detained by security agents in Tehran on August 22.

There also have been reports of arrests in the Kurdish-populated area of western Iran - from where Amini originated - that were the scene of the earliest protests.

Kurdish-focused Hengaw, based outside Iran, said Saro Mostajer - the brother of one of its board members, Jila Mostajer - had been arrested in Amini's hometown of Saqez and taken to an unknown location.

Boroumand said the "coordinated" repression "aims at preventing the dissemination of news, videos and images of victims, commemorations, and other gatherings and avoid a renewed public mobilization inside and outside Iran."

Ghaemi warned the "silence of the international community" in the face of the crackdown risked giving a "green light to the state security apparatus to continue muzzling civil society."