The Syrian capital Damascus was hit by a power cut late on Wednesday, shortly after an explosion near the international airport, residents said.
"The whole city just went dark," said a resident who lives in the centre of the city and asked to remain anonymous.
An AFP journalist in Damascus said he could see from a distance a huge fire blazing near Damascus International Airport, which is located near the affected power station.
A Damascus resident told Al Jazeera on Thursday morning that power had been restored in most of the capital.
State news agency SANA quoted Electricity Minister Imad Khamis as saying that electricity in "all provinces" had been cut off due to "a terrorist attack on the gas pipeline feeding the electricity generating stations in the southern region."
"A terrorist attack on a gas pipeline that feeds a power station in the south has led to a power outage in the provinces, and work to repair it is in progress," Emad Khamis said on Wednesday.
The Syrian Observatory for Human Rights, a UK-based group that reports on abuses and battlefield developments using sources from both sides of Syria's civil war, said the explosion was caused by rebel artillery that hit a gas pipeline near the airport.
The Observatory said the rebel shelling was aimed at the town of Ghasula, a few kilometres from the airport. Rebels have been trying to push into the capital, a stronghold of President Bashar al-Assad, whose family has ruled Syria for four decades.
"It is likely this was a large-scale operation planned well in advance," said Observatory director Rami Abdel Rahman.
In September, a similar outage was caused after a high-voltage power line was sabotaged.