Syria lost Internet connectivity for more than seven hours in more than 95 percent of the country Thursday — its longest outage since last May — but no one really knows why.

Last year, three such major Internet outages made some analysts wonder whether the Syrian government has a “kill switch,” as reported by Mashable in 2013.

Screen shot from Renesys, a firm that tracks computer servers and has been monitoring Syria. Four networks experienced an outage in Syria starting at 12:26 UTC on March 20. This represents 95% of the routed networks in the country. One-hundred percent of the networks in this event reached the Internet through: Syrian Telecommunications Establishment.

A screen shot from Renesys, a firm that tracks computer servers and has been monitoring Syria. Four networks experienced an outage in Syria starting at 12:26 UTC on March 20, representing 95 percent of the routed networks in the country.

Thursday’s outage was notable because of its size and duration. Many Western reporters stay in contact with sources on the ground through various Internet telecommunication applications, and many family members, government agencies and those involved in intelligence rely on the Internet for real-time information coming from the civil war-torn country.

Analysts said they aren’t certain what caused Thursday’s nationwide outage, whether it was triggered by government design or shelling near sensitive cables because of the ongoing conflict.

Renesys, an company that tracks Internet data and intelligence, noted that the blackout started at 8:30 a.m. ET.  The firm, which has been monitoring Syria’s Internet since the start of the war, was the first to notice that roughly 84 networks experienced the outage.

Syria’s outages are often on a much smaller scale. On Friday, a smaller outage was reported in the city of Aleppo, lasting approximately two hours, according to a report from Syria Deeply, a nonprofit organization monitoring the Syrian conflict.

On its website, Syria Deeply said it was unclear what caused the massive blackout. It could be the “result of deliberate network shutdowns by the Syrian Telecommunications Establishment, the government arm that controls the country’s internet, and what is the result of technical problems caused by fighting in the areas near the communications cables.”

Others telecommunication analysts noted it may have been caused by war damage from bombs or other shrapnel disabling the systems.

Doug Madory, senior analyst at Renesys, Syria Deeply that the outage was “the longest since May of last year, if you count minutes. Last May was eight hours and 20 minutes, and this one was seven hours and 20 minutes. There have been a bunch of national blackouts in the last year, but a lot of times they’re of a shorter duration than that.”

“If you go back to 2011, there’s been a number of different scenarios. One interesting thing I hadn’t thought about recently was that their first Internet blackout was in June 2011, and in that time they did a selective outage where they just knocked out mobile and residential networks but left government networks online: things like the oil ministry and a few other random things,” he told the website. ”At that time, we said that maybe the government had learned from from what happened in Egypt that they don’t want to knock everything off, just knock off the things you don’t want on.”

Follow Sara A. Carter (@SaraCarterDC) on Twitter

Other Must-Read Stories