Protests over gasoline prices have swept across some 100 cities and towns in Iran, turning violent faster than widespread economic protests in 2017 and rallies over the country's disputed 2009 presidential election.
The scale of the unrest that began on Friday remains unclear as authorities have shut down the internet across this nation of 80 million people.
Prior to that, online videos purported to show people abandoning their cars on major highways and marching on city centers. Demonstrations devolved into violence as rioters set fire to gas stations, attacked banks and robbed stores.
While sparked by President Hassan Rouhani's decision to raise government-set gasoline prices, the protests take root in decades-old economic problems, exacerbated by the US pullout of Iran's nuclear deal with world powers and re-imposed economic sanctions.
And though some protest chants directly challenge Iran's Shiite theocracy, its government has the manpower and experience to quickly put down demonstrations.
PUTTING OUT FIRE WITH GASOLINE
DEMONSTRATIONS QUICKLY ESCALATE IN IRAN
COMMUNICATION BREAKDOWN
It called Iran's shutdown the most severe "in terms of its technical complexity and breadth."
The internet firm Oracle called it "the largest internet shutdown ever observed in Iran."
ECONOMIC WOES
CRACKDOWN LOOMS