Iran's internet is slowly returning after a six-day blackout that left the country with little way of communicating amid widespread demonstrations over rising fuel prices.

Protests erupted across the country after Iran’s government announced Friday that it was going to start rationing gasoline and increase fuel prices by 50 percent. Reports of casualties linked to the government’s crackdown are mixed, but human rights group Amnesty International said Tuesday it believes more than 100 people have been killed during the protests.

At its lowest point, Iran’s connectivity to the outside world fell to 4 percent of ordinary levels, according to the nonprofit group Netblocks, which monitors worldwide internet access.

“The ongoing disruption is the most severe recorded in Iran since President [Hassan] Rouhani came to power, and the most severe disconnection tracked by NetBlocks in any country in terms of its technical complexity and breadth,” Alp Toker, the director of Netblocks, wrote on the organization’s website.

Iran’s internet began to come back online Thursday, according to Reuters and local news agencies.

Rouhani said in a meeting with Cabinet members Nov. 15 that the price hike was meant to collect money for low-income people who have been hit by the country’s economic struggles. The justification didn’t soothe frustrated Iranians, who took to the streets in several major cities Friday afternoon, using their cars to block roads and highways.

Update: 90 hours after #Iran implemented a near-total internet shutdown, connectivity continues to flatline at just 5% of ordinary levels 📉



Iranians deserve access to the outside world like everyone else #Internet4Iran #IranProtests



📰https://t.co/1Al0DT8an1 pic.twitter.com/32QZ9Vhbol — NetBlocks.org (@netblocks) November 20, 2019

U.S. sanctions brought in after President Donald Trump’s decision to withdraw from the 2015 nuclear deal have strangled the Iranian economy. Under these sanctions, all U.S. companies are banned from doing business with Iran.

Governments around the world have moved in recent years to limit or cut off internet access during times of civil strife. In the last few months, the governments of Iraq, Algeria and Venezuela have cut off internet access in their countries during intense uprisings.

Toker said that they started to notice mobile and fixed-line outages in Tehran, Mashhad, Shiraz and other cities in which citizens were protesting Friday.

Because the outages did not have a national impact at that point, evidence collected by Netblocks indicated that those cities were being specifically targeted in order to make it more challenging for people to organize, Toker said.

As protests intensified into Saturday, Iran’s largest mobile network operators all fell offline, leaving people inside the country with little to no means of communicating online. The outage has also meant little information about the protests has made it out of Iran over the past few days.

Iranians living abroad have reported trouble reaching family back home.

“Like most Iranians, we have a family WhatsApp group,” Arash Azizi, a doctoral student at New York University, said on Twitter. “ My grandmother, when she gets up for her morning prayers at around 5 a.m., always starts the day by wishing us a good morning "under the care of God. The group has now been silent for 3 days and it eats me from the inside.”

People protest against increased gas price, on a highway in Tehran, Iran, on Nov. 16, 2019. Nazanin Tabatabaee / West Asia News Agency via Reuters

Azizi told NBC News that he had finally received some news from his family through family friends who reached them via landline. He added that the phone lines were also not working very well.

Iranians are used to censorship and internet disruptions but not on this scale. In 2009 and 2011, the government used bandwidth throttling to quell protesters. The internet was painfully slow, but Iranians were still able to connect to the outside world. They could also rely on VPNS, and other digital tools to get around censored websites and social platforms.

The ongoing disruption was also complex in a way that analysts say they have never seen before. The government managed to pull most of the country offline, all the while keeping their critical infrastructure, such as hospitals and banks, up and running with their via the government’s local network.

The minister of telecommunications told reporters Monday that the government’s network, known as the National Information Network (NIN), “had made significant progress” and that the internet would be restored “soon”