Mohammad Nayeb-Zehi was among the hundreds of worshippers who gathered on September 30 at the Great Mosalla, a religious site in Iran's southeastern city of Zahedan, for Friday Prayers.

Just hours later, the 16-year-old's family learned he was dead.

Nayeb-Zehi was among the scores of people gunned down by security forces in a brutal crackdown following anti-government protests in Zahedan, the provincial capital of Sistan-Baluchistan Province, which is home to the country's Baluch minority.

"He was a simple laborer and not political," Nayeb-Zehi's brother, Ahmad, told RFE/RL's Radio Farda in a telephone interview from Zahedan, adding that his sibling had been shot in the heart. "We're in pain, and we cannot accept it."

The crackdown in Zahedan came amid weeks-long nationwide protests triggered by the death of Mahsa Amini, a 22-year-old who died on September 16, days after she was detained by Iran's morality police.

In Sistan-Baluchistan, public anger at the authorities escalated amid reports that a 15-year-old Baluch girl had been raped by a police official in the province's southern port city of Chabahar.

The violence erupted soon after protesters gathered outside a police station near the central mosque in Zahedan. Members of the crowd chanted anti-government slogans, and some threw rocks. Security forces responded with deadly force by firing on the crowd from the station, according to witnesses.

Security forces also raided the central mosque and the nearby Great Mosalla and opened fire on worshippers using live ammunition, rights groups said, adding that many were shot in the head, heart, neck, or torso, revealing a clear intent to kill or seriously wound.

At least 94 people were killed and 350 wounded on that day, referred to as "Bloody Friday," according to the U.S.-based Iran Human Rights Documentation Center. At least 13 minors were among those killed, including Nayeb-Zehi.

The victims were overwhelmingly Baluch -- a mostly Sunni ethnic group that has long faced disproportionate discrimination at the hands of the Iranian authorities.

"He was martyred inside the Mosalla while holding his prayer mat," said Ahmad Nayeb-Zehi.

Nayeb-Zehi's family first visited Zahedan's Khatam al-Anbia hospital, hoping he was among the wounded. They later found his body in a seminary at the Great Mosalla.

"We entered a room there and saw about 10 bodies," said Ahmad Nayeb-Zehi. "[Mohammad] was among them."

He said the authorities prevented the family from filming the scene. "I told them this has to be documented, it has to be published by international media," he said, adding that footage later emerged on social media showing the gruesome scene at the seminary.

The family refused to send Nayeb-Zehi's body to the morgue. Instead, his body lay in the living room for around 24 hours before he was buried.

"We said he was martyred and there was no need for an autopsy," said Ahmad Nayeb-Zehi.

The authorities accused Jaish al-Adl, a Sunni militant group, of attacking the police station. The group is recognized as a terrorist organization by both Iran and the United States and has previously claimed deadly attacks in Sistan-Baluchistan targeting Iranian security forces.

But local and independent sources have rejected the authorities' claims.

The authorities have also reported a much lower number of fatalities, announcing that only 19 people, including several members of the security forces, were killed.

Ahmad Nayeb-Zehi said the authorities were "rubbing salt into the wounds of the people" by claiming "terrorists" were involved.

He said he witnessed a military helicopter shooting at civilians near the Great Mosalla. "I haven't even seen such scenes in Hollywood movies," he said. "A helicopter was shooting at people. A lady was shot in front of my eyes."

RFE/RL could not verify his account. But activists have accused security forces of shooting at protestors from helicopters.

"I don't know what the intention of this crime was," he said. "Our only demand from the establishment is for the murderers of our [family members] to be punished."

The killings have led to widespread anger in Sistan-Baluchistan, one of Iran's poorest provinces.

Anti-establishment protests have been reported in Zahedan since the crackdown, including on October 14 and October 21, when protesters took to the streets after Friday Prayers and chanted "Death to the dictator."

During his Friday Prayers sermon on October 21, influential Sunni cleric Molavi Abdolhamid Ismaeelzahi said senior officials, including Supreme Leader Ayatollah Ali Khamenei, were "responsible" for the September 30 killings.

"We are surprised by the silence of the high-ranking officials," he said in his sermon, which was posted on his website.

"Scores were killed here without any reason. I don't have the exact number. Some have reported 90, some say less, some say more," Ismaeelzahi added.

He also said people will not be satisfied until "those who killed the people" are brought to justice.

The Iran Human Rights Documentation Center said the events of September 30 amounted to "a massacre of protesters by security forces."

"The government's total denial of responsibility for the massacring of citizens by its security apparatus is consistent with similar past denials and is evidence that internal calls for investigation of such crimes are insufficient," said the rights group, which documents human rights violations in Iran.

(KB/RFE-RL)