Iran has hanged a man who had been convicted of killing two members of security forces, the judiciary’s Mizan news agency reports, the second execution linked to anti-government protests in less than a week.

Nationwide protests, in their third month, erupted after the death of 22-year-old Kurdish Iranian woman Mahsa Amini on September 16 in the custody of morality police enforcing strict mandatory dress code laws.

The demonstrations turned into a popular revolt by furious Iranians from all layers of society, posing one of the worst legitimacy challenges to the clerical leadership since the 1979 revolution.

“Majid Reza Rahnavard was hanged in public in [the holy Shi’ite city of] Mashahd this morning … he was sentenced to death for ‘waging war against God’ after stabbing to death two members of security forces,” Mizan said on Monday.

Activists on social media criticised the execution of the 23-year-old Mr Rahnavard as “a criminal act” by the clerical establishment to deter dissent.

Iran’s hanging of another young man, Mohsen Shekari, last Thursday convicted of injuring a security guard with a knife and blocking a street in Tehran during protests, has been widely condemned by the US and its allies.

Rights groups said Mr Shekari was tortured and forced to confess.

Amnesty International said Iranian authorities were seeking the death penalty for at least 21 people in what it called “sham trials designed to intimidate those participating in the popular uprising that has rocked Iran“.

Iran’s state media aired footage of a man, which they identified as Mr Rahnavard, stabbing another man who fell against a parked motorcycle, and then stabbing another person immediately after.

Mizan said Mr Rahnavard was arrested when trying to flee the country 23 days ago. It added that his sentence was upheld by a higher court.

Rights group HRANA said that as of Sunday 488 protesters had been killed, including 68 minors. It said 62 members of Iran’s security forces had also been killed.

As many as 18,259 protesters were believed to have been arrested, it said.

While the United Nations said the protests had cost more than 300 lives, a top Iranian state security body has said that 200 people, including members of the security forces, had died in the unrest.

– AAP