DUBAI, United Arab Emirates (AP) — 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 U.S. 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

For Iranians, cheap gasoline is practically considered a birthright. Iran holds the world’s fourth-largest crude oil reserves. As jobs remain scarce, many Iranians work as informal taxi drivers. But subsidizing prices both benefited Iran’s wealthy and spurred gasoline smuggling to neighboring countries.

The International Energy Agency estimates that Iran spent more than any other nation in the world to subsidize fossil-fuel costs in 2018 — $69 billion in total. Over $26 billion went toward oil subsidies, the IEA said.

Previous pushes to cut the subsidies sparked protests, so Rouhani’s government changed prices early Friday — at the start of the weekend in Iran — with no warning. The new prices are seeing consumers pay 13 cents a liter (49 cents a gallon) on their first 60 liters a month. After that, they pay 26 cents a liter (98 cents a gallon).

Even with those hikes, Iran remains one of the cheapest places in the world to buy gasoline.

A gallon of regular unleaded gasoline costs on average $2.59 in the U.S., according to AAA.

DEMONSTRATIONS QUICKLY ESCALATE IN IRAN

Since the price hike, demonstrators have abandoned cars along major highways and joined mass protests in the capital, Tehran, and elsewhere. Some protests turned violent, with demonstrators setting fires as gunfire rang out.

It remains to be seen how many people were arrested, injured or killed. Iranian authorities on Sunday raised the official death toll in the violence to at least three. However, that figure may be low. Videos from the protests have shown people gravely wounded.

The semiofficial Fars news agency, close to the country’s Revolutionary Guard, reported Sunday that demonstrators had ransacked some 100 banks and stores in the country. Authorities arrested some 1,000 people, Fars reported, citing unnamed security officials for the information.

COMMUNICATION BREAKDOWN

Part of the reason it remains difficult to know what’s happening in Iran is because authorities have shut down access to the internet. Since late Saturday night, access went from worse to nonexistent across the nation. That stopped the spread of online videos of the demonstrations and affected the ability of protesters to share information.

The group NetBlocks, which monitors worldwide internet access, said connectivity had fallen to just 7% of ordinary levels. It called Iran’s shutdown the most severe “in terms of its technical complexity and breadth.”