Anas Qtiesh (@Anas) and Rainey Reitman contributed to this report.

Earlier today, we learned that Internet traffic between Syria and Western online services had plummeted drastically, indicated that the country's connection to the wider Internet had been shut down. Reports from Renesys and Google confirmed the routes into Syria had been withdrawn, implying either a massive infrastructure cut, or a deliberate silencing of online communication. The details of the situation in Syria are still unknown, but we’re deeply concerned that this blackout is a deliberate attempt to silence Syria's online communications and further draw a curtain over grave events currently unfolding on the ground in Syria.

Google Transparency Report shows Syrian Internet blackout May 7, 2013

According to Dan Hubbard of Umbrella Security Labs: “At around 18:45 UTC OpenDNS resolvers saw a significant drop in traffic from Syria. On closer inspection it seems Syria has largely disappeared from the Internet.” Hubbart notes that the two top-level domain servers for Syria (ns1.tld.sy and ns2.tld.s) were unreachable earlier today. Matthew Prince at Cloudflare published a video demonstrating just how the routes into and out of Syria's Internet were withdrawn.

This is not the first time Syria has suffered an Internet shut down. In November 2012, Syria suffered a severe Internet black out. And as the violence in the region has escalated, we’ve documented campaigns of targeted malware attacks against Syrian activists.

Syrians have been suffering an unprecedented humanitarian crisis as the uprising against the Assad regime turned into a violent civil war encompassing the entire country. The uprising in Syria began in March 2011 as part of the Arab Spring revolutions with protesters taking to the streets to demand the resignation of President Bashar as-Asaad. The Human Rights Data Analysis Group has analyzed evidence of mass killings in the region and found 59,648 unique, identifiable records of killings between March 2011 and November 2012. Most foreign media were banned and expelled from Syria in 2011.

Yet during this time the Internet has largely remained available. While heavily censored, monitored, and compromised, the Internet has served as an important window connecting the world at large to Syria, and one way that international observers could connect with individuals on the ground in that country. A number of activists on the ground in Syria have access to Internet via satellite links, which can connect them to the Internet but carries a high risk for detection, which can be life threatening.

We are continuing to monitor the situation in Syria. Information and resources are being shared on Twitter using the hashtag #syriablackout.