Syria, including the capital Damascus, suffered large scale blackouts after an explosion at a gas pipeline.
Much of the country was left without power when artillery, said to be fired by rebels, struck a gas pipeline that supplies a power station.
Residents say the entire capital has been affected by powercuts.
The UK-based activist group the Syrian Observatory for Human Rights said rebel shelling had been aimed at the town of Ghasula, around 2km from the airport.
It said the attack was a wide scale operation planned well in advance.
In another development, weapons inspectors say they are confident Syria will meet an important early milestone for destroying all equipment used in chemical weapons.
Martin Nesirky, spokesperson of the Secretary-General, United Nations said: “The Joint Mission of the Organisation for the Prohibition of Chemical Weapons (OPCW) and the United Nations dealing with Syria’s chemical weapons programme reports that it has now visited 18 of the sites disclosed by Syria. The team adds that Syria’s work to render critical equipment inoperable has begun at nearly all those sites.”
According to the timetable backed up by a UN security council resolution passed last month, Syria must complete the destruction of its entire arsenal by the middle of next year