Three members of the Iranian security forces have been stabbed to death by "rioters" near Tehran, ONA reports citing ISNA.
The assailants wielding knives and machetes ambushed the three - a Revolutionary Guard and two members of the Basij militia - west of the capital, the news agencies reported.
The deaths take to at least five the number of people confirmed to have been killed in violent demonstrations that erupted across Iran on Friday against a surprise petrol price hike.
One of the three was identified as Morteza Ebrahimi, a commander of the Islamic Revolutionary Guard Corps and father of a newborn child.
The other two were Majid Sheikhi, 22, and Mostafa Rezaie, 33. Both served in the Basij militia, a volunteer force loyal to the establishment.
State television said a ceremony would be held for Ebrahimi and Rezaie in Tehran on Tuesday afternoon.
Ongoing protests across the country have killed at least five people and put renewed pressure on Iran's government as it struggles to overcome US sanctions.
The full scale of the protests, which began shortly after a 50 per cent increase in gas prices took effect early Friday, remains unknown after Tehran shut down the internet over the weekend, blocking Iranians from sharing videos and information with the outside world.