Iran said it executed two men Saturday convicted of allegedly killing a member of the security forces during unprecedented nationwide protests sparked by the death of 22-year-old woman Mahsa Amini in custody on Sept. 16.

The two men executed on Saturday had been convicted of killing a Basij paramilitary force militia member. Three others have been sentenced to death in the same case, while 11 received prison sentences.

"Mohammad Mehdi Karami and Seyyed Mohammad Hosseini, principal perpetrators of the crime that led to the unjust martyrdom of Ruhollah Ajamian, were hanged this morning," the judiciary said in a statement carried by the official IRNA news agency.

The latest executions bring to four the number of protesters officially known to have been executed in the aftermath of the unrest.

Amnesty International said last month that Iranian authorities are seeking the death penalty for at least 26 others in "sham trials designed to intimidate protesters in the popular uprising that has rocked the country."

It said all those facing death sentences had been denied the right to adequate defense and access to their chosen lawyers. Rights groups say defendants have instead had to rely on state-appointed attorneys who do little to defend them.

Amnesty said the court that convicted Karami, a 22-year-old karate champion, relied on forced confessions.

Hosseini's lawyer Ali Sharifzadeh Ardakani said in a Dec. 18 tweet that Hosseini had been severely tortured and that confessions extracted under torture had no legal basis.

He said Hosseini was beaten with his hands and feet tied up, kicked in the head until he passed out, and subjected to electric shocks on different body parts.

Iran denies that confessions are extracted under torture.

Mahsa Amini died in custody in September after being arrested by morality police enforcing the country's mandatory dress code laws. The ensuing protests represent one of the biggest challenges to the Islamic Republic since its establishment in 1979.

Supreme Leader Ayatollah Ali Khamenei on Saturday named hardline police official Ahmad Reza Radan as the new national police commander, state media reported.

Radan, placed under the United States sanctions in 2010 for human rights violations, frequently called for strict enforcement of the country's dress code for women during his earlier police positions.

The Basij force, affiliated with Iran's powerful Revolutionary Guards, has been behind much of the crackdown against protesters.

Iran has blamed the unrest on its foreign foes, including the U.S., and sees its crackdown on protests as preserving national sovereignty.

The rights group HRANA said 517 protesters had been killed during the unrest as of Friday, including 70 minors. It said 68 members of the security forces had also been killed.

It said that as many as 19,262 protesters are believed to have been arrested.

Iranian officials have said that up to 300 people, including members of the security forces, have died.

The first protester knew to be executed, 23-year-old Mohsen Shekari, on Dec. 8, less than three months after his arrest. He was accused of burning a trash bin, blocking a road, stabbing a member of the Basij militia with a machete, and threatening public safety.

Majid Reza Rahnavard, 23, was hanged from a crane in public on Dec. 12 in the northeastern city of Mashhad, less than a month after his arrest. He was accused of stabbing to death two Basij members and wounding four other people in Mashhad.