TBILISI, Georgia -- All of Georgia was without power for the entire day on Monday, and officials in the impoverished former Soviet republic were struggling to determine the cause of the blackout.
Electricity went off at 7 a.m. in the entire country of 4.4 million people and was not fully restored until about 10 p.m.
Periodic blackouts are common here -- and rolling blackouts are regularly implemented to conserve power -- but it was the first time in two years that the whole country was affected at once.
"We are trying to figure out what's happening," said Medeya Kakhadze, an aide to Fuel and Energy Minister Mamuka Nikolaishvili. "We know only that an emergency shutdown occurred."
Telasi, the electricity utility, refused to comment.
Many Georgians have their own diesel generators. Hospitals and airports also have their own energy supplies in case of emergency.
But Tbilisi's subway did not open in the morning and electric-powered trolley buses were unable to run, leaving regular buses overflowing with passengers, many of whom hung onto the doors.
City residents were also without water because electric pumps failed.
Tbilisi has experienced sporadic power supplies for the past week. On Sunday, residents of one city district stormed a dispatch unit and forced workers to turn on the power in their neighborhood.
Natural gas supplies also have been cut off in the city for the past two weeks. Officials say the gas lines are being repaired.
Monday's blackout came on Nikolaishvili's first work day as energy minister and followed the recent sale of a 75 percent stake in Telasi by the Arlington, Va.-based AES Corp. to Russia's UES.
Georgia is heavily dependent on Russia for energy, and many politicians, including President Eduard Shevardnadze, had criticized the acquisition, warning that it would give Russia a powerful political lever in dealing with Georgia.
UES head Anatoly Chubais this month sought to reassure Shevardnadze, saying the company had no political goals and Georgia's electricity supplies would be safe.