Dozens of people were killed as a result of firing by Iranian security forces on demonstrations after Friday prayers in the southeastern province of Sistan-Baluchistan.
According to news agencies AFP and Reuters, Iran has stepped up its crackdown on protests that began after the death of Mahsa Amini.
Demonstrators this week called for nationwide demonstrations in solidarity with Kurdistan.
In a video from Zahedan, the capital of Sistan-Baluchistan, one of Iran's few Sunni-majority cities, protesters were heard chanting "Kurdistan, Kurdistan, we will support you" on Friday.
Activists later said security forces opened fire on protesters in the city.
The London-based Baloch Activist Campaign said on its Telegram channel that "dozens of people have been killed or injured."
AFP is unable to estimate the number of casualties and injuries.
BAC shared a video showing a group of men carrying a man who appeared to be injured outside Makkah Mosque in Zahedan.
According to BAC, protesters also came out on the streets of Iranshahr, Khash and Sarawan cities of Sistan Balochistan.
"The Islamic Revolutionary Guard Corps used military equipment, including heavy machine guns, to suppress people," says the Oslo-based group Iran Human Rights.
Revolutionary Guards have strengthened their presence in Kurdish areas.
The Kurdish-populated provinces of western and northwestern Iran have been hotbeds of protests since Mehsa Amini's death.
On Tuesday, the International Health Regulations (IHR) said that Iranian security forces have killed at least 416 people, including 51 children and 27 women, since the protests began.
126 people were killed in Sistan Balochistan and 48 people were killed in Kurdistan province.
On September 30, more than 90 people were killed during a mass shooting in Zahedan.
Friday's protests came a day after the UN Human Rights Council voted in favor of a high-level investigation into Iran's bloody crackdown.
Iran condemned the move, saying it was a "violation of the country's national sovereignty."
