In a slow, relentless advance, a catastrophic Hurricane Dorian kept pounding at the northern Bahamas early Monday, as one of the strongest Atlantic storms ever recorded left wrecked homes, shredded roofs, tumbled cars and toppled power poles in its wake.

The storm's top sustained winds decreased slightly to 170 mph (275 kph) as its westward movement slowed, crawling along Grand Bahama island early Monday at 2 mph (4 kph) in what forecasters said would be a daylong assault. Earlier, Dorian churned over Abaco island with battering winds and surf during Sunday.

Strong winds move the palms of the palm trees at the first moment of the arrival of Hurricane Dorian in Freeport. AP

There was little information from the affected islands, though officials expected many residents to be left homeless. Most people went to shelters as the storm approached, with tourist hotels shutting down and residents boarded up their homes.

"It's devastating," Joy Jibrilu, director general of the Bahamas' Ministry of Tourism and Aviation, said Sunday afternoon. "There has been huge damage to property and infrastructure. Luckily, no loss of life reported."

On Sunday, Dorian's maximum sustained winds reached 185 mph (297 kph), with gusts up to 220 mph (354 kph), tying the record for the most powerful Atlantic hurricane to ever make landfall. That equaled the Labor Day hurricane of 1935, before storms were named. The only recorded storm that was more powerful was Hurricane Allen in 1980, with 190 mph (305 kph) winds, though it did not make landfall at that strength.

Forecasters said Dorian was most likely to begin pulling away from the Bahamas early Tuesday and curving to the northeast parallel to the U.S. Southeast seaboard. Still, the potent storm was expected to stay close to shore and hammer the coast with dangerous winds and heavy surf, while authorities cautioned that it could still make landfall.

South Carolina Gov. Henry McMaster issued an order Sunday for the mandatory evacuation of his state's entire coast. The order, which covers about 830,000 people, was to take effect at noon Monday, at which point state troopers were to make all lanes on major coastal highways one-way heading inland.

"We can't make everybody happy, but we believe we can keep everyone alive," McMaster said.

A resident of Amelia Island sunbathes before storms hit the coast before Hurricane Dorian in Jacksonville, Florida. Reuters

A few hours later, Georgia's governor, Brian Kemp, ordered mandatory evacuations for that state's Atlantic coast, also starting at midday Monday.

Authorities in Florida ordered mandatory evacuations in some vulnerable coastal areas. North Carolina Gov. Roy Cooper warned his state that it could see heavy rain, winds and floods later in the week.

Dorian first came ashore Sunday at Elbow Cay in Abaco island at 12:40 p.m., then made a second landfall near Marsh Harbour at 2 p.m.

"Catastrophic conditions" were reported in Abaco, with a storm surge of 18 to 23 feet (5.5-7 meters).

People are seen running from pouring rain on the shore in Lantana Beach, Florida. Eva Marie Uzcategui/AFP

Video that Jibrilu and government spokesman Kevin Harris said was sent by Abaco residents showed homes missing parts of roofs, electric lines on the ground and smashed and overturned cars. One showed floodwaters rushing through the streets of an unidentified town at nearly the height of a car roof.

In some parts of Abaco, "you cannot tell the difference as to the beginning of the street versus where the ocean begins," Prime Minister Hubert Minnis said. According to the Nassau Guardian, he called it "probably the most sad and worst day of my life to address the Bahamian people."

Bahamas radio station ZNS Bahamas reported that a mother and child on Grand Bahama had called to say they were sheltering in a closet and seeking help from police.

Associated Press