Power restored in Adelaide's north

Power has been restored to a majority of the North Adelaide properties affected by an early morning outage which took out traffic lights and forced a number of businesses to throw away food.

The outage was first reported around 5am on Friday and left approximately 268 properties without power at its peak.

Motorists were advised to avoid O'Connell Street as it was without working traffic lights, with Main North Road, Barton Terrace and Chapel Street also affected, South Australian police said.

The likely cause of the outage was maintenance crews hitting a underground cable while doing gas works overnight, SA Power Networks said.