In this image courtesy of the US Coast Guard, boats are seen strewn across a marina in Andros Island, Bahamas. (AFP)

Weakening slightly but still packing a powerful punch, Hurricane Dorian churned towards the southeastern coast of the United States on Tuesday after delivering a devastating blow to the Bahamas.

Bahamas National Security Minister Marvin Dames said several children were among the seven deaths reported in the Atlantic archipelago from the monster storm and predicted more fatalities.

“I can’t see any way out of it,” the Nassau Guardian newspaper quoted Dames as telling reporters.

Prime Minister Hubert Minnis said “we can expect more deaths to be recorded.”

Aerial footage of Great Abaco Island in the Bahamas broadcast by CNN showed scenes of catastrophic damage, with hundreds of homes missing roofs, overturned cars, widespread flooding and debris strewn all over.

“This was a crisis of epic proportions,” Dames said. “Maybe the worst that we’ve experienced, certainly in our lifetime.”

View of a flooded street in downtown Nassau. (AFP)

The runways at Grand Bahama International Airport in Freeport, the island’s largest city, were under water, complicating rescue and recovery efforts.

The online Bahamas Press published video of flooding in the Rand Memorial Hospital in Freeport and said patients had been forced to evacuate.

The US Coast Guard sent MH-60 Jayhawk helicopters to Andros Island in the southern Bahamas to help with search and rescue operations as residents trapped in their homes by floodwaters issued distress calls.

Bahamas Press published pictures and the names of people who have been reported missing by their relatives on Abaco island.

Ken Graham, director of the Miami-based National Hurricane Center (NHC), said Dorian was on the move after being “stationary for more than 24 hours battering the Bahamas.”

Dorian, which has dumped as much as 30 inches (76 centimeters) of rain on the Bahamas, was downgraded Tuesday morning from a Category 3 to a Category 2 storm on the five-level wind scale.

But it remained an extremely dangerous hurricane as it moved toward the coast of the southern US states of Florida, Georgia and South and North Carolina.

A state of emergency has been declared up and down the coast for millions of US residents potentially in the path of the storm.

The Pentagon said 5,000 members of the National Guard and 2,700 active duty troops were ready to help out if needed.