HONOLULU (Hawaii) - MUCH of the Hawaiian island of Oahu was left without power overnight into early on Saturday, including the area where president-elect Barack Obama is vacationing, after a huge blackout plunged the island into darkness.

Portable generators were provided to the Obama family on Friday night, government sources said, after more than 900,000 residents and tourists of the international vacation destination were hit by the blackout when thunderstorms rolled across Oahu, possibly causing a lightning strike on a generator facility.

Witnesses in the Kailua area, on the southeast coast of Oahu about 10 miles (16 kilometres) from Hawaii's largest city Honolulu, said the power came back on at 6 am (12am Singapore time) on Saturday on the street where the Mr Obama's luxury rental is located - about 12 hours after the power outage.

All resorts, homes and businesses in and around Honolulu, including near the famed Waikiki Beach, were dark overnight, according to an AFP photographer.

Honolulu Mayor Mufi Hannemann said he contacted Obama at 9.30 pm on Friday and that the president-elect said they were holding up well and were going to bed early, CNN reported.

A rare Hawaii thunderstorm caused an interruption in power at about 6.30 pm on Friday, shutting down all but one of the Hawaiian Electric Company (HECO) power stations, with the final plant going offline at 8.30 and leaving all of Oahu in the dark, local station KHNL TV reported.

'We are reenergising the system. It has to be done in a very methodical fashion... to make sure that the grid is stable,' HECO official Darren Pai, told station KITV.

The blackout came amid a frenzy of post-Christmas shopping, leaving shoppers stranded in darkened shopping malls, motorists grappling with traffic signal malfunctions, and several outbound flights postponed to Saturday. -- AFP