Iran kills over a hundred protesters in just three days of demonstrations
The rights group revealed comes just hours after a UN office raised alarm that dozens of protesters may have been killed as authorities begin to open fire on demonstrations sparked by petrol price hikes, however, quickly spiralled into calls for the regime's fall.
It added that the true figure of those killed may be as many as 200, but a near-total internet blackout in force since Saturday continues, making it difficult to verify reports of casualties.
Amnesty's findings came after verifying video footage and gathering eyewitness testimonies and information from activists outside Iran to reveal what it called a "harrowing pattern of unlawful killings" by Iran's security forces.
The group added that top officials, including Supreme Leader Ayatollah Ali Khamenei had given the green light to the lethal crackdown through speeches that smeared the demonstrators as "hooligans" and "rioters", and calling on security forces to "implement their duties".
Video footage received by the group shows security forces using firearms, water cannons and tear gas to break up protests, as well as beating demonstrators with batons.
Images of bullet casings scattered on the streets indicate that authorities used live ammunition, which could feasibly have led to the high death toll.
Eyewitnesses reported to Amnesty that security forces were taking the dead and injured away from the streets and hospitals, so that the causes of death and injuries could not be recorded.
State media said on Saturday that over a thousand protesters had been arrested since protests began.
Iran's powerful armed force the Revolutionary Guards vowed on Wednesday to launch "decisive" action against protesters if they did not desist.
Similar crackdowns on past protest movements have led to dozens of deaths and mass imprisonment of peaceful activists.
"The authorities must end this brutal and deadly crackdown immediately and show respect for human life," said Philip Luther, Research and Advocacy Director for the Middle East and North Africa at Amnesty International.
"The frequency and persistence of lethal force used against peaceful protesters in these and previous mass protests, as well as the systematic impunity for security forces who kill protesters, raise serious fears that the intentional lethal use of firearms to crush protests has become a matter of state policy," he added.
The highest number of casualties had occurred in the cities of Bandar-e Mahshahr, Javanroud and Kermanshah, according to Amnesty's figures.
Iranians face their fourth day without internet on Tuesday, with connectivity being cut to four percent, according to cybersecurity NGO Netblocks.
"The internet will come back gradually in some provinces where there are assurances the internet will not be abused," government spokesman Ali Rabiei said.
The outage has stemmed the flow of videos shared on social media of protests or associated acts of violence.
"Shutting down communications over the internet is a systematic assault on the right to freedom of expression and suggests that the authorities have something to hide," said Amnesty's Philip Luther.
"Iranian authorities must immediately lift all restrictions on access to the internet and social media to allow people to share information and freely express their opinions."
Tehran on fire
Reports of at least two petrol stations set on fire in the capital emerged on Tuesday, backed up by video footage of the buildings ablaze and later put out with water cannons.
Banks and other public property has reportedly been set on fire and shops looted, as protesters vent their anger over sudden price increases on fuel by at least 50 percent.
However, most of the demonstrations have been peaceful, according to Amnesty's report.
Authorities have homed in on outbreaks of protester violence, with state television broadcasting footage of masked young men clashing with security forces.
State news agencues also reported that knife and machete-wielding assailants ambushed and killed three security personnel west of Tehran on Monday.
Petrol price hikes
Iran's government announced on Friday the price of petrol would be raised by 50 percent for the first 60 litres purchased over a month and 200 percent for any extra fuel after that.
The measure heightens an already severe economic downturn in Iran, triggered in May last year when the United States unilaterally withdrew from a 2015 nuclear agreement and reimposed crippling sanctions on the Islamic republic.
The government says the hikes - which come just months before parliamentary elections - will create revenue to provide financial aid to the country's neediest households.
Agencies contributed to this report.