Anger flared after the 22-year-old Iranian Kurd's death on September 16, three days after her arrest in Tehran by the notorious morality police for an alleged breach of the Islamic republic's strict dress code for women.

Iran said on Friday an investigation found Amini had died of a longstanding illness rather than "blows" to the head, despite her family reportedly saying she had previously been healthy.

But the women-led protests continued even as ultraconservative President Ebrahim Raisi posed for a group photograph with students at Tehran's all-female Al-Zahra University to mark the new academic year.

Young women on the same campus were seen shouting "Death to the oppressor", said the Oslo-based group Iran Human Rights (IHR).

In Amini's hometown Saqez, in Kurdistan province, schoolgirls chanted "Woman, life, freedom" and marched down a street swinging headscarves in the air, in videos the Hengaw rights group said were recorded on Saturday.