As citizens continue to protest in Iran, reports reveal that the government has begun blocking Internet access and social media in an attempt to prevent protests.

Fortune reports that the Iranian government has begun blocking access to the Internet in an attempt to stop protests. Reports from inside the country claim that the government began blocking Internet access on December 30 in an attempt to prevent protesters from communicating with each other. Protests, however, are still going ahead:

Iranian internal minister Abdolreza Rahmani-Fazli claimed in a statement that some individuals on social networks were “causing violence and fear.” Pavel Durov, the CEO of Telegram, an encrypted messaging service, stated on Twitter that the Internet shutdown followed “our public refusal to shut down… peacefully protesting channels.” Durov said in a blog post that the company “would rather get blocked in a country by its authorities than limit peaceful expression of alternative opinions.”

“How nervous the government is about losing control over the population is proportional to various control tactics they implement over the Internet,” Mahsa Alimardani, a researcher on Internet freedoms, told Motherboard. “In the past few hours there are also some reports of home connections (up until today mostly left undisturbed) also facing some blocks to accessing foreign web content.”

Initially, it was believed that only social media access had been blocked, but the Saudi-backed news service Al Arabiya reported that Iranian telecommunication companies have blocked Internet access entirely in multiple cities. Many Iranian ISPs are allegedly owned by or closely linked to the Iranian Revolutionary Guard, a military group with substantial influence across the country.

The current protests in Iran are the largest since the 2009 “Green Revolution,” in which Twitter and other social media companies played a significant role in protest organization.