Iranians chant slogans against supreme leader at memorials for slain protesters
The country's clerical authorities also staged a commemoration in the capital Tehran to mark the 40th day since the deaths at the peak of the protests on January 8 and 9, in line with Shiite mourning tradition.
Officials acknowledge more than 3,000 people died during the unrest, but attribute the violence to "terrorist acts", while rights groups say many more thousands of people were killed, shot dead by security forces in a violent crackdown.
The protests, sparked by anger over the rising cost of living before exploding in size and anti-government fervour, subsided after the crackdown, but in recent days Iranians have chanted slogans from the relative safety of homes and rooftops at night.
On Tuesday, videos verified by AFP showed crowds gathering at memorials for some of those killed again shouting slogans against the theocratic government in place since the 1979 Islamic revolution.
In videos geolocated by AFP shared on social media, a crowd in Abadan in western Iran holds up flowers and commemorative photos of a young man as they shout "death to Khamenei", referring to Iran's supreme leader, and "long live the shah", in support of the ousted monarchy.
Another video from the same city shows people running in panic from the sounds of shots, though it wasn't immediately clear if they were from live fire.
In the northeastern city of Mashhad a crowd in the street chanted, "One person killed, thousands have his back", another verified video showed.
Gatherings also took place in other parts of the country, according to videos shared by rights groups.
Official commemorations
At the government-organised memorial in Tehran crowds carried Iranian flags and portraits of those killed as nationalist songs played and chants of "Death to America" and "Death to Israel" echoed through the Imam Khomeini Grand Mosalla mosque.
Iranian President Masoud Pezeshkian attended a similar event at the Imam Reza shrine in Mashhad.
Authorities have accused sworn enemies the United States and Israel of fuelling "foreign-instigated riots", saying they hijacked peaceful protests with killings and vandalism.
Senior officials, including First Vice President Mohammad Reza Aref and Revolutionary Guards commander Esmail Qaani, attended the ceremony.
"Those who supported rioters and terrorists are criminals and will face the consequences," Qaani said, according to Tasnim news agency.
International organisations have said evidence shows Iranian security forces targeted protesters with live fire under the cover of an internet blackout.
The US-based Human Rights Activists News Agency (HRANA) has recorded more than 7,000 killings in the crackdown, the vast majority protesters, though rights groups warn the toll is likely far higher.
More than 53,500 people have been arrested in the ongoing crackdown, HRANA added, with rights groups warning protesters could face execution.
Tuesday's gatherings coincided with a second round of nuclear negotiations between Iran and the United States in Geneva, amid heightened tensions after Washington deployed an aircraft carrier group to the Middle East following Iran's crackdown on the protests.