The Iranian regime triggered an internet "kill switch" in an apparent effort to hide alleged abuses by security forces and as protests against it surged nationwide, a cybersecurity expert has claimed.

The blackout slashed internet access to a fraction of normal levels on the 13th day of the protests as rights groups, including current blackout is among the most severe it has ever recorded in Iran.

"We are tracking near-total disconnection of internet service across Iran right now, and connectivity is below 2% of ordinary levels," Toker said.

"This is a nationwide disruption that is impacting almost all services, all connectivity and all avenues of life, extending beyond just mobile phones and computers," he said.

"It’s impacting banks, essential services, and there’s very little communication within the country, so people are unable to reach the outside world and nobody has the ability to communicate."

Despite the sweeping restrictions, some limited communication channels remain available, Toker revealed.

"There are a few gaps, so it's possible to communicate with those close to the borders through Wi-Fi or mobile service that crosses borders," he said.

"It’s also occasionally possible to find a part in the service, in a fixed-line service, where they can tunnel through all those, but that is increasingly rare and no longer an option. 

"Another mechanism we’ve seen is access via satellite internet, namely the Starlink network, but the equipment is banned by the Iranian regime."

"The technology that the Iranian regime uses to trace links is essentially anti-espionage technology," he said.

"These measures are typically imposed by the most authoritarian regimes, the most controlling governments that seek to silence and oppress their own populations," Toker said.

"NetBlocks tracked very similar multi-week disruption in 2019, during which thousands were killed, and this was also done in 2022 when people were protesting the killing of Mahsa Amini."

"In past incidents, we did observe that the government attempted to keep a baseline of service available.

"In this recent case, they pulled the plug, so there’s a far more extreme measure in place here, which suggests that the regime is scared and isn’t taking risks when it comes to the possibility of information reaching the outside world."

President Donald Trump warned Iran’s leaders Friday against using force on protesters.

Speaking to reporters at the White House, he warned Iran was in "big trouble."

"I just hope the protesters in Iran are going to be safe, because that’s a very dangerous place right now," Trump said. "You’d better not start shooting, because we’ll start shooting, too."

"The U.S. has encouraged democracy in Iran, and that’s a positive thing at this point," Toker said.

"There’s very little that can be done from the outside, but it’s important to continue to support positive efforts.

"A free and open internet in Iran, and indeed in other countries, can encourage democracy and support basic liberties," he added.