Internet traffic in Syria has slowed to an effective standstill, according to a pair of US technology companies monitoring web traffic. Rebel fighters, meanwhile, have reported clashes for control of Damascus airport.
US companies Akamai and Renesys said on Thursday that Syrian Internet activity had ground almost to a halt as of 12:26 local time (1026 GMT), with coverage staying down throughout the afternoon.
"In the global routing table, all 84 of Syria's IP address blocks have become unreachable, effectively removing the country from the Internet," Renesys wrote on its blog.
Several news agencies reported that residents had noticed only sporadic coverage for their cell phones and some disturbances for landlines as well.
Localized blackouts have taken place in the past during Syria's lengthy conflict, but Thursday's was thought to be the first nationwide loss of coverage.
"As the atrocities in Syria continue, now the Internet and telephone connection are shut down. Really scary #SyriaBlackout," EU Home Affairs Commissioner Cecilia Malmström wrote on her Twitter account, using the signature "CM" to denote that she had written the entry herself.
The blackout also interrupted the news feed of Syria's state-run SANA news agency.
Fighting reported around Damascus airport
Activist groups, including the British-based Syrian Observatory for Human Rights, reported heavy fighting on Thursday around Damascus' airport, as rebel forces apparently sought to gain control of the site. The airport is situated roughly 15 kilometers (9.3 miles) to the east of the city center.
"The road to Damascus International airport was closed because of ongoing fighting and military operations in the surrounding areas," the Observatory said.
As with most reports coming out of Syria, the information could not be independently verified owing to restrictions on access for international press - though state television later acknowledged the clashes, saying that the road had been reopened.
"The road from the airport was secured after attacks by armed terrorist groups against cars and after a deployment of the competent forces," the broadcaster said, citing the Information Ministry.
The Syrian Observatory for Human Rights estimates that more than 40,000 people have died in Syria since the civil war broke out in March last year between forces loyal to President Bashar Assad and those seeking a change in government.
International envoy Lakhdar Bramini was also due to brief the Security Council on the situation in Syria on Thursday, an address that looked set to be overshadowed by the General Assembly vote in New York on recognizing the Palestinian Territories as an observer member of the UN.
msh/hc (AFP, dpa, Reuters)