Update: Web monitoring firms are reporting that Syria is returning to the internet after web traffic from the troubled country hit zero last night.
In total, the internet was down for around 19 and a half hours - a state-run news agency claims that the downtime was due to an "optic cable malfunction".
Original story continues:
The internet has been effectively switched off in Syria as web monitoring companies report zero traffic coming from the country since last night.
The Syrian government claims that terrorists are behind the blackout, although some have speculated that the government itself shut down access to mask what's actually happening across the country.
The Electronic Frontier Foundation is of this thinking, saying that, "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.
"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."
It's not the first time that Syrian citizens have been prevented from accessing the internet; it was shut down for three days in November 2012 as well.
Throughout the Arab Spring uprisings across the Middle East, removing internet access has become a weapon used to hinder communication and obscure what's happening on the ground to the rest of the world. Libya and Egypt both suffered blackouts as well as Syria.
While web access is still out in Syria, it seems that mobile phones and landlines are both working as normal in the country.