The number of people missing since debris-laden flash floods smashed through the community of Montecito in southern California is now five, authorities have said, down from as many as 43 on Thursday.

Santa Barbara County spokeswoman Amber Anderson said the number had dropped because many people were located, but it could continue to fluctuate.

She said some missing-person reports are rapidly cleared while others take a long time to resolve.

(PA Graphics)
(PA Graphics)

The number of confirmed deaths remains at 17.

Ms Anderson said the number of personnel searching ravaged neighbourhoods has doubled over the past day to 1,250.