Residents in some areas were forced to seek temporary shelter because of the loss of electricity that began Friday and lasted nearly 24 hours, the Saudi Gazette said .
Officials said they were calling for an investigation into the incident and more than 250 workers were on hand installing temporary generators. Utility officials told the newspaper it was the biggest blackout in regional history.
Abdolmoein al-Sheik, director of utility operations for Western Saudi Arabia, told the newspaper the blackouts were likely related to the weather.
"Overload or poor maintenance were not the real culprits," he said. "Bad weather is likely responsible." The region has been plagued by heavy thunderstorms, he said.
The incident hit the holy city of Mecca. The state utility company said the two main generators in the region were operating at only 20 percent of their full capacity before the blackout, indicating poor maintenance or overload were not to blame, al-Sheik said.