"In some areas, it is possible to access the Internet but with great difficulty," Observatory director Rami Abdel Rahman told AFP.
"It is also very difficult to reach people by phone. But we have received reports that it is possible to communicate between certain regions via fixed telephone lines," he added.
AFP correspondents noted that Internet and telephone communications, including mobile phones, were cut in the capital.
The official news agency SANA had still not resumed transmission Friday after its feed was cut on Thursday at midday. Its website was also inaccessible.
On Thursday afternoon, when communications were first cut in Syria, activists accused the regime of preparing a "massacre" while the authorities explained this interruption as "maintenance".
The United States on Thursday accused the Syrian regime of cutting off Internet and telecommunications links in the war-torn country, branding the move a sign of desperation.
Amnesty International said on Twitter that reports of an Internet shutdown were "very disturbing".
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