(waves lapping) ♪ ♪ >> NARRATOR: This is Iran.

A country where young people film and share their lives every day on social media.

(crowd chanting in Farsi) >> NARRATOR: This is also Iran, an Islamic republic ruled by a supreme religious leader, Ayatollah Ali Khamenei.

♪ ♪ In September 2022, anti-government protests swept across the coountry after the death of a young woman in police custody.

>> (chanting in Farsi): (guns firing) >> NARRATOR: In the crackdown that followed, human rights groups estimate more than 500 Iranians have been killed, including 72 children.

>> (chanting in Farsi): >> NARRATOR: Since the start, young Iranians have been filming the violence themselves and posting it online.

(weapon firing, people screaming) ♪ ♪ Independent and foreign media are largely banned here, but "Frontline" has been able to gather and review over a hundred hours of this footage, cross-checking it with testimony from eyewitnesses and protesters... >> The sound of the guy breathing while he raped me still echoes in my ears.

>> NARRATOR: ...and following activists and exiles who are trying to expose what is happening in Iran.

>> (shouting and cheering) >> (speaking Farsi): >> (screams) (paintball gun fires) ♪ ♪ >> (speaking Farsi): >> NARRATOR: Awin Mostafazadeh is a human rights activist who fled Iran in 2007.

For years, her organization has been working with reporters and other activists inside Iran, documenting abuses against the Kurdish minority.

On September 13, 2022, she got news from Tehran that a young Kurdish woman named Mahsa "Zhina" Amini was in a coma after being beaten by Iran's morality police.

>> (speaking Farsi): (device beeps, object bumping in video) >> NARRATOR: Mahsa, who was also known by her Kurdish name, Zhina, was 22 years old and about to start university.

She'd come to Tehran on a day trip.

The morality police-- enforcers of Iran's Islamic dress code-- had arrested her accusing her of not being covered appropriately.

As word spread, people began to gather near the hospital.

Some were filming on their phones.

>> (shouting) (speaking Farsi): (continues shouting, woman sobbing) (woman 1 shouting in video) >> (speaking Farsi): (traffic humming, car horn honks) >> NARRATOR: Shiva Nazarahari is a human rights activist who was jailed four times in Iran for anti-government activities.

She fled the country in 2018, and has been working from exile in Europe.

She agreed to let us film her gathering testimony about what happened after Mahsa Amini fell into a coma.

>> (speaking Farsi): (compact shuts) >> (speaking Farsi): (laughs) >> NARRATOR: Leyla is speaking from inside Iran.

>> (speaking Farsi): >> LEYLA: >> NARRATOR: Leyla says she rushed to the hospital after she saw the photo of Mahsa Amini in a coma on Instagram, and found the crowd of protesters gathering there.

The scene was captured on footage we obtained.

>> LEYLA: >> NARRATOR: On September 16, news got out that Mahsa Amini had died.

A female journalist got into the hospital and photographed her grieving relatives.

The picture spread quickly on Twitter.

>> (speaking Farsi): >> NARRATOR: The Iranian government did not grant any interviews for this film, or respond to a list of questions.

Shortly after Mahsa Amini's death, Tehran's police released edited CCTV footage of her collapsing at a police station.

They denied beating her and said she'd had a heart attack, and they'd done everything to keep her alive.

>> (speaking Farsi): (woman screaming, man shouting) >> NARRATOR: Before her death, videos showing abuses by the morality police had been circulating on Iranian social media, fueling resentment against the regime.

In some cases, the government said it had punished officers involved.

>> (speaking Farsi): (woman screaming) >> (speaking Farsi): >> (speaking Farsi): ♪ ♪ (crowd chanting in Kurdish) >> (sobbing, speaking Kurdish) (crowd chanting in Kurdish) >> NARRATOR: At the funeral in the Kurdish town of Saqqez, mourners began to chant, "Woman, life, freedom."

(crowd chanting) It would become the slogan of a new movement which would quickly spread beyond the Kurdish minority and rally women across the country.

>> (speaking Farsi): (crowd chanting in Kurdish) (crowd cheering and applauding) >> NARRATOR: After footage of the funeral spread on social media, women took to the streets, filming their own acts of defiance.

>> (speaking Farsi): >> (speaking Farsi): (car horns honking, people whistling) >> NARRATOR: The protests began to spread around the country.

>> (chanting in Farsi): >> NARRATOR: In the weeks that followed, women across Iran removed their hijabs.

(car horns honking) >> (speaking Farsi): (crowd cheering and applauding) (crowd cheering in video) (crowd clapping in rhythm and chanting) (crowd cheers and applauds) (crowd chanting in Farsi) (crowd cheers and applauds) ♪ ♪ >> NARRATOR: Before Iran became an Islamic republic, it was ruled by the Western-backed Shah Mohammad Reza Pahlavi.

His regime was repressive, and employed a brutal security service that imprisoned opponents.

But women had the right to dress freely and be a substantial part of the workforce.

(glass shatters) (bottles clinking) (crowd chanting in Farsi) After a revolution in 1979, Ayatollah Khomeini took power and the constitution was rewritten to reflect Islamic law.

(crowd chanting in Farsi) The hijab was made compulsory for all women in public.

>> In Iran, women marched in support of a modern identity.

>> (chanting in Farsi) >> The shah pulled the chador down by force.

These people are putting it up by force.

>> Men eventually attacked the protesters.

Several of the women who stood their ground with considerable courage were stabbed.

>> (chanting in Farsi) >> NARRATOR: In the decades that followed, women have repeatedly risen up in protest.

>> (chanting in Farsi): >> NARRATOR: But Iran remains an authoritarian Islamic state under a supreme leader, Ayatollah Ali Khamenei, who has refused to grant women more freedoms.

After the death of Mahsa Amini, he dismissed the protests as a plot by Iran's enemies.

>> (speaking Farsi) (crowd shouting) (cheering) (cheering loudly, applauding) >> NARRATOR: Iranian authorities said they were investigating what happened to Mahsa Amini.

>> (chanting in Farsi): >> NARRATOR: But the unrest continued to spread.

Protesters were burning their hijabs and sharing the footage with the world.

♪ ♪ (crowd chanting in Farsi) >> (speaking Farsi): >> (speaking Farsi): (crowd cheers and applauds) (chanting in Farsi): >> (speaking Farsi): (crowd cheers and applauds) ♪ ♪ >> NARRATOR: Zar Amir Ebrahimi was once a famous TV actor in Iran.

In 2008, she fled the country after a private intimate video was leaked.

She was sentenced to 99 lashes and banned from appearing on television.

(audience cheers and applauds) She is now an international movie star.

>> (speaking Farsi): (people talking in background) >> NARRATOR: Zar has been gathering testimony from inside Iran about the uprising, and sharing it with journalists and human rights organizations.

>> (speaking Farsi): >> (speaking Farsi): >> NARRATOR: Nasrin had a teenage daughter, Nika.

>> (speaking Farsi): >> (speaking Farsi): (laughing with audience) (singing, audience clapping and cheering) (stops singing, laughing) (singing): (girl talking from audience) (resumes singing): >> (speaking Farsi): >> (singing softly and babbling) >> (speaking Farsi in video): >> (speaking Farsi) >> (speaking Farsi in interview): >> (chanting in Farsi): >> NARRATOR: On September 20, Nika joined a protest in Tehran.

Footage we've verified shows her waving her headscarf and setting it on fire.

(crowd chanting and cheering) (chanting continues) >> (speaking Farsi): (crowd cheering) >> NARRATOR: More footage shot that day shows Nika throwing rocks in the direction of the police.

Another clip, recorded that night, shows Nika still at the protest, taking cover behind a car.

>> (speaking Farsi): >> NARRATOR: Nika's family says her Instagram and Telegram accounts were deleted that night.

They began to search for her, and told the authorities she was missing.

>> (speaking Farsi): (sighs) >> NARRATOR: Nika's death certificate stated that she "died due to multiple injuries caused by the impact of a hard object."

>> CNN has looked at the final hours of Iranian teenager Nika Shakarami, who was among the many protesters on the streets days after Amini's death.

>> NARRATOR: Her death became an international news story.

The authorities denied any wrongdoing, but gave conflicting accounts.

First, they told her family she'd been killed by an opposition group.

Then state media published CCTV footage purporting to show Nika entering a building after the protest.

>> (speaking Farsi): NARRATOR: They claimed she later jumped, or was pushed, off the roof.

>> (speaking Farsi): ♪ ♪ (chanting in Farsi, clapping in rhythm) >> (speaking Farsi): (in interview): ♪ ♪ (people clamoring, car horns honking) >> NARRATOR: The regime went on the offensive.

(siren wailing in distance) (people screaming, weapons firing) According to a leaked Iranian army document, on September 21, security units across the country were given an order to "severely and seriously confront rioters."

(people shouting) The authorities began to round up journalists.

They arrested the reporter who had published the photo of Mahsa Amini's grieving family, and her Twitter account was suspended.

They also began to restrict internet access across the country... >> (speaking Farsi): >> (speaking Farsi): >> WOMAN: (device buzzes, people shouting) >> NARRATOR: ...and to remove footage of the uprising from social media sites by forcing protesters to close their accounts.

(people shouting) (weapon fires) (gun fires) >> (speaking Farsi): (guns firing) >> NARRATOR: But videos of the crackdown continued to spread.

(men shouting) >> (speaking Farsi): (shouting continues) (woman screaming) >> (gasps, speaking Farsi) >> (speaking Farsi): (vehicle horns honking, protesters clamoring) >> NARRATOR: This clip was filmed on the night of September 21.

(honking continues) (motorbike engine revving) >> (speaking Farsi): (people shouting and whistling, traffic humming) (video continues) (horns honking, man speaking Farsi) (gun fires) ♪ ♪ >> NARRATOR: The man was identified by Iranian activists as Pooria Alipour, a 30-year-old building engineer.

He survived the attack.

Iranian police have said they are investigating the video and that "the offending police officers will certainly be dealt with according to the law."

>> (speaking Farsi) >> (speaking Farsi, laughs) >> (laughs) >> NARRATOR: Sarina Esmailzadeh was a teenage YouTuber from the city of Karaj.

Her videos were about food, makeup, and music.

>> (speaking Farsi): (cheers) >> (speaking Farsi): >> (speaking Farsi): >> NARRATOR: In the months before the uprising, some of Sarina's posts were about politics.

>> (speaking Farsi): (tone beeps) (protesters chanting) >> NARRATOR: When the protests reached Sarina's home city, the authorities responded with force.

Footage filmed there during the early days of the uprising shows security forces beating people on the streets.

(firing) (woman chanting, cars honking) On September 22, Sarina joined one of the protest.

(people shouting) (weapon firing) She never returned.

Human rights groups say that Sarina died of head injuries, like Nika.

Eyewitnesses told local activists she was beaten to death with police batons.

The authorities said she jumped off a building.

>> (speaking Farsi): >> (speaking Farsi): (tone beeping) >> (chanting in Farsi): >> (speaking Farsi): >> NARRATOR: As news of the deaths of Sarina and Nika spread, something remarkable happened.

Schoolgirls across Iran began to hold protests of their own.

(girls chanting in Farsi) Despite internet blackouts imposed by the government, videos went viral showing extraordinary acts of defiance.

Schoolgirls filmed and shared footage of themselves defacing pictures of the supreme leader-- a crime under Iranian law.

>> (speaking Farsi): >> (speaking Farsi): >> (cheering) >> (chanting in Farsi): >> (speaking Farsi): (girls shouting in Farsi) >> NARRATOR: In Sadra High School in Karaj, the students chased away a government official.

(girls chanting) >> (chanting): >> (cheering) >> (speaking Farsi): >> (chanting in Farsi): >> (speaking Farsi): >> (chanting in Farsi): (car horns honking) >> (speaking Farsi): (car horns honking) >> (speaking Farsi): Okay.

>> NARRATOR: Even in exile, the Kurdish activist Awin Mostafazadeh is often on the move between safe houses.

She fears she could be arrested and forcibly returned to Iran.

(door unlocking) >> (speaking Farsi): (car horns honking) >> NARRATOR: From the very beginning, Iran's Kurdistan province was the epicenter of the uprising.

Mahsa Amini's death had inflamed long-held grievances here.

For decades, Iranian Kurds have accused the regime of discrimination.

Amid escalating clashes between protesters and security forces the regime launched a series of offensives in the Kurdish areas.

Awin has been gathering evidence about what happened.

>> (clapping in rhythm, chanting) >> (speaking Farsi): >> NARRATOR: Yahya, who is now in exile, was one of the protest leaders in the city of Mahabad.

(sirens wailing) >> (speaking Farsi): (guns firing) (man shouting in world language) >> (speaking Farsi): (weapons firing) (man exclaiming in world language) (weapons firing) (woman screams in distance) (automatic guns firing, woman gasping softly) (sobbing) (guns fire, people screaming in distance) >> (speaking Farsi): (guns firing) >> NARRATOR: In a statement at the time, Iran's Revolutionary Guard said it was confronting "terrorist separatist groups" in the Kurdish areas, and that "dealing decisively with terrorists is our mandate."

(explosion pounds in distance) (guns firing, man panting) (man murmuring) (guns firing, man panting) So far, Awin says she has confirmed the deaths of at least 125 protesters in Kurdish cities since the start of the crackdown.

She's been talking to eyewitnesses like Keivan, a medical student.

He was working with a team of volunteers to treat wounded protesters, and has since fled Iran.

>> (speaking Farsi): >> NARRATOR: Keivan says he was arrested for helping the protesters and taken to a secret detention center.

His account of what happened next is horrific.

>> (speaking Farsi): >> (speaking Farsi): >> (speaking Farsi): ♪ ♪ >> NARRATOR: Iran has denied abusing prisoners, but Keivan's account echoes the testimony of many other detainees.

Since the beginning of the uprising, thousands of protesters have been arrested and locked up in regime black sites or police stations, like the one in this video from the city of Karaj, posted online in September.

>> NARRATOR: Zar is taking the testimony of a man who is still inside Iran and asked for his identity to be concealed.

He says he was held in a black site in the Northwest of of the country after being arrested at a protest in October.

>> (speaking Farsi): >> (sniffles) >> NARRATOR: In November, the crackdown escalated.

>> (speaking Farsi): (audience responding) >> NARRATOR: The regime began to prosecute protesters.

Many were charged with the religious crime of moharebeh-- waging war against God.

(singing in Farsi, guitar playing) >> (speaking Farsi): >> NARRATOR: In his trial, he was also accused of blocking a road and attacking a regime militiaman.

Mohsen was convicted of waging war against God and was executed by hanging on the morning of December 8.

>> (wailing in Farsi): (screaming) (sobbing) >> NARRATOR: Footage from that day shows a family member mourning his death.

The video went viral.

>> (chanting in Farsi): >> (speaking Farsi): >> NARRATOR: By the summer of 2023, seven protesters had been executed-- some convicted of killing security forces.

Seven others were on death row.

♪ ♪ The mass street protests have died down for now.

(man singing) >> NARRATOR: But the uprising continues with hundreds of small acts of defiance.

♪ ♪ >> Whooo!

♪ ♪ ♪ ♪ (music fades) >> NARRATOR: Families of the dead continue to speak out, despite the risks.

>> (speaking Farsi): ♪ ♪ >> (sighs) (speaking Farsi): ♪ ♪