Debris extended for kilometres and floods covered much of the Bahamas in the wake of Hurricane Dorian, in what the archipelago’s prime minister called one of the worst disasters to ever strike the island nation.

“Parts of Abaco are decimated. There’s severe flooding, there’s severe damage to homes, businesses, other buildings and infrastructure,” said Prime Minister Hubert Minnis, warning the death toll could rise.

Emergency workers struggled to reach victims as search and rescue operations continued into Wednesday and the scope of the damage and humanitarian crisis unfolded.

The massive Atlantic storm churned towards the United States on Wednesday after leaving seven dead in the Bahamas.

Aerial footage showed scenes of catastrophic damage with hundreds of homes missing roofs, cars submerged or overturned, widespread flooding and boats reduced to matchwood.

Dorian, which has dumped as much as 76 centimetres of rain on the Bahamas, was downgraded on Tuesday morning to a Category 2 hurricane on the five-level wind scale and a state of emergency has been declared in parts of the east coast for millions of US residents potentially in its path.