Iranian police are reported to have fired on protesters in Saqqez, according to witnesses, reports BBC.
Saqqez is the home city of Mahsa Amini who died in custody after being arrested for wearing her hijab "improperly".
Thousands of protesters gathered near the grave of the Amini and clashed with the police force, even after 40 days of her death.
A rights group and witnesses said officers fired live rounds and tear gas at the crowds in the city.
Protests swept across Iran after Ms Amini, 22, died on 16 September.
She had been detained three days earlier by the morality police in the capital, Tehran, and fell into a coma after collapsing at a detention centre.
On Wednesday, security forces were deployed in Saqqez and other parts of Kurdistan province, in anticipation of fresh demonstrations on the 40th day of mourning for Ms Amini - a culturally significant occasion for Iranians.
Videos showed thousands of mourners walking along a road, through a field and across a river to bypass roadblocks and reach the graveyard where Ms Amini is buried.
The crowds were heard shouting "Woman, life, freedom" and "Death to the dictator" - two of the signature chants of the protest movement - as well as "Down with traitors" and "Kurdistan will be the graveyard of fascists".
Kurdish human rights group Hengaw, which is based in Norway, later tweeted that mourners had marched towards the provincial government's office in Saqqez and that security forces had opened fire on people in Zindan square.
Reuters news agency quoted an unnamed eyewitness as saying: "The riot police shot mourners who gathered at the cemetery... Dozens have been arrested."
Bd-pratidin English/Lutful Hoque
