An explosion severed an underground gas pipeline near Damascus, cutting power to the city and outlying suburbs on Friday evening, electricity minister Ghassan Al Zamil said.
Mr Al Zamil told state news agency Sana the vital pipeline had been hit by anti-government rebels, a common occurrence since the start of the 2011 civil war.
The gas line supplied the Deir Ali power station, one of the largest thermal power plants in Syria which supplies over 800 megawatts of electricity to the capital, home to over 2 million people.
"There was a significant direct drop in gas pressure, which led to the failure at the Deir Ali power station... as a result of an attack on the gas line," Mr Al Zamil told Sana.
Sana said repair work was under way on the line, and by Saturday morning power had reportedly returned across much of Damascus.
Syria has suffered a worsening electricity crisis in recent years, despite a reduction in violence across much of the country as a decade-long civil war draws to a close.
Most areas of Syria receive between two and 10 hours of electricity a day.
But power cuts on a large scale are rare, with the last notable outage happening in August 2020 when a gas line feeding three power stations near Damascus was cut by a blast.
In March 2016, much of the country suffered an electricity outage following a similar attack.