Demonstrators marched in Iran's restive southeast on Friday amid reports on social media that security forces were surrounding a mosque at the center of weekly anti-government rallies.
Anti-government protests have been taking place across Iran since last September's death in custody of 22-year-old Kurdish Iranian woman Mahsa Amini for flouting hijab policy, which requires women to entirely cover their hair and bodies.
"We swear on our comrades' blood to stand strong until the end," hundreds of demonstrators were seen chanting in a video from the flashpoint city of Zahedan posted by the activist news agency HRANA.
Another widely-circulated video purported to show security forces beating and arresting a Baluch man trying to enter the Makki Mosque in Zahedan, capital of Sistan-Baluchistan province.
Reuters could not immediately verify the videos.
The Baluch minority, estimated to number up to 2 million people, has faced discrimination and repression for decades, according to rights groups. Sistan-Baluchistan, bordering Pakistan and Afghanistan, is one of Iran's poorest provinces and has seen repeated killings by security forces in recent years.
Zahedan saw one of the deadliest days of protests after Amini's death, with at least 66 people killed in a crackdown there on Sept. 30, Amnesty International said.
As with previous bouts of unrest, authorities appeared to have disrupted internet services on Friday.
"Confirmed: Real-time network data show a significant disruption to internet connectivity in Zahedan, #Iran; the incident comes amid a growing security presence during Friday protests," NetBlocks internet monitor said.
There was no immediate word on state media of Friday's protests. Tehran says the protests are instigated by its foreign enemies.
Meanwhile, Iran's currency continued its slide to hit new lows, weighed by the unrest and Tehran's increased isolation under mounting Western sanctions.
The rial plummeted to a new record low of 539,200 against the US dollar on Friday, compared to 526,500 on Thursday, according to foreign exchange site Bonbast.com, amid reports of new sanctions against Iran.
The US Commerce Department targeted Belarus, Iran and others in its latest response to Russia's invasion of Ukraine, imposing export control measures and adding more targets to its entity list.
While the nationwide unrest has diminished in recent weeks, probably because of executions and crackdowns, acts of civil disobedience have continued from anti-government graffiti to unveiled women appearing in public.
