Hurricane Florence may have been downgraded to a tropical depression but American authorities on Sunday warned that the worst is yet to come as catastrophic flooding continued to spread, pushing the death toll to 17.

Roy Cooper, governor of North Carolina, said: "The risk to life is rising with the angry waters."

The storm continued its lingering crawl westward, dumping more than 30 inches of rain in some places since Friday.

Tens of thousands more were ordered to evacuate their homes as rivers threatened to burst their banks, bringing the risk of flash flooding.

Mr Cooper said the storm had "never been more dangerous than it is now", with waters expected to peak on Monday in some places.