NORTH CAROLINA (Reuters) - Flooding in the aftermath of Hurricane Matthew has displaced several thousand people in North Carolina, and authorities were helping more evacuate on Tuesday (Oct 12) as swollen rivers threatened a wide swath of the state.

Governor Pat McCrory said the storm-related death toll in North Carolina has been raised to 19.

He warned of "extremely dangerous" conditions in the coming days in central and eastern North Carolina, where several rivers were at record or near-record levels.

Matthew, the most powerful Atlantic storm since 2007, killed at least 1,000 people in Haiti last week before barreling up the US south-eastern coast and causing at least 30 deaths in Florida, Georgia and the Carolinas.

Nearly 4,000 people have taken refuge in North Carolina shelters, including about 1,200 people in the hard-hit Lumberton area, where the Lumber River had crested at almost 1.2m above the prior record set in 2004 after Hurricane Frances.

Water blanketed the city of 21,000 people, leaving businesses flooded, homes with water up to their roof lines and drivers stranded after a stretch of Interstate-95 became impassable.

About 532,000 homes and businesses remained without power in the US south-east on Tuesday, down from the peak of around 2.2 million on Sunday morning when the storm was still battering the Carolina coasts.