At least 537 people were killed by Iranian security forces during the violent crackdown on protests for the death of the 22-year-old Kurdish woman Mahsa Amini, the non-governmental organization Iran Human Rights (IHR) said today.

In its previous report, the IHR spoke of 488 dead protesters.

This new report, marking 200 days since Mahsa Amini’s death, includes new and completely cross-referenced evidence of protester deaths, the Norway-based NGO claims.

The most protester deaths were recorded in September (223), October (100) and November (173), according to Iran Human Rights.

Iran has been rocked by an unprecedented protest movement following the death of Mahsha Amini on September 16, three days after she was arrested by morality police in Tehran on charges of violating the Islamic Republic’s strict dress code for women.

For their part, Iranian authorities say that several members of the security forces are among the hundreds of people who have died during the episodic protests. They also note that in recent weeks, participation in these protests has declined.

Most of the dead protesters come, according to the IHR, from the province of Sistan-Baluchistan (134), a degraded region in southeastern Iran where – unlike the rest of the territory – the Sunni element is strong.