The latest in a line of internet blackouts in civil war-stricken Syria prompted Google to encourage Syrians with phone access to use its Speak2Tweet service to maintain online communications.
A statement from Google on Tuesday evening said: "Internet access has been completely cut off in Syria in the past few hours. Mobile phones and landlines may not be working properly either. But those who still have a phone connection can still use Speak2Tweet by leaving a voicemail on one of these international phone number.
"No internet connection is required and people can listen to the messages by dialling the same phone numbers of going to twitter.com/speak2tweet."
Reports on Wednesday suggested internet coverage was coming back up after the outage, which the Syrian state news agency said was the result of a fault in optical fibre cables.
Syrians have experienced internet outages within the last two years of civil war with accusations flying between government and rebel forces over responsibility.