Updated 9.22pm

Tropical Storm Florence dumped "epic" amounts of rain on North and South Carolina as it trudged inland on Saturday, triggering dangerous flooding, toppling trees, cutting power to nearly a million homes and businesses while causing at least six deaths.

Florence's intensity has diminished since it roared ashore along the U.S. mid-Atlantic coast on Friday as a hurricane. But its slow march over the two states, crawling west at only 2 miles per hour (3 km per hour), threatens to leave much of the region under water in the coming days.

"This system is unloading epic amounts of rainfall, in some places measured in feet and not inches," North Carolina Governor Roy Cooper told a news briefing about a storm that forecasters said was 300 miles (480 km) wide.

With flood waters rising rapidly in many communities, people trapped in homes awaited rescue, while tens of thousands hunkered down in shelters after fleeing their homes as the storm approached. Authorities warned about potential landslides and numerous roads were closed.

Utility crews worked to restore electricity. An estimated 772,000 people remained without power in North Carolina, 172,000 in South Carolina.

A tree rests on a newly-built house in Belville, North Carolina. Photo: ReutersA tree rests on a newly-built house in Belville, North Carolina. Photo: Reuters

In Wilmington, a city of about 120,000 on North Carolina's Atlantic coastline along the Cape Fear River that is home to historic mansions and a decommissioned World War Two-era battleship, streets were strewn with downed tree limbs and carpeted with leaves and other debris. Electricity remained out for much of the city, with power lines lying across many roads like wet strands of spaghetti.

'A blessing'

"The fact that there haven't been more deaths and damage is amazing and a blessing," said Rebekah Roth, walking around Wilmington's Winoca Terrace neighborhood.

The National Hurricane Center said the storm would dump as much as 30 to 40 inches (76-102 cm) of rain on the southeastern coast of North Carolina and part of northeastern South Carolina, as well as up to 10 inches (25 cm) in southwestern Virginia.

Fayetteville, a city of about 210,000 people about 90 miles (145 km) inland, issued a mandatory evacuation order for thousands of residents near Cape Fear River because of flooding. Fort Bragg, a sprawling U.S. Army base, is just west of Fayetteville.

At 2 p.m. EDT (1500 GMT), the hurricane center said Florence had maximum sustained winds near 45 miles per hour (75 km per hour) and continued to produce catastrophic flooding in the Carolinas. It said it was located about 50 miles (65 km) west of Myrtle Beach, South Carolina, and forecasters predicted a slow westward march.

Cooper said many people in his state who may think the storm has missed them have not yet seen its actual threat to their regions, advising residents inland that rivers will rise days after the rain has stopped.

In some places, the US Army was brought in to rescue people. Photo: ReutersIn some places, the US Army was brought in to rescue people. Photo: Reuters

He said five deaths were confirmed from the storm in North Carolina and "several others are under investigation," and urged people to heed evacuation orders.

Authorities in South Carolina reported their first death from the storm, saying a woman died in a car crash on Highway 18 in Union County late on Friday when the roof of her vehicle struck a fallen tree.

Florence already has set a North Carolina record for rainfall totals, exceeding that of Hurricane Floyd, which struck in 1999 and caused 56 deaths. Floyd produced 24 inches (61 cm) of rain in some parts of North Carolina while Florence already has dumped about 30 inches (76 cm) in areas around Swansboro.

"It's like being stalked by a turtle," Federal Emergency Management Agency official Jeff Byard told reporters.

On Thursday, Florence was a Category 3 hurricane on the five-step Saffir-Simpson scale with 120-mph winds (193 km). It was downgraded to Category 1 before coming ashore on Friday near Wrightsville Beach, near Wilmington.

In New Bern, at the confluence of the Neuse and Trent rivers in North Carolina, Florence overwhelmed the town of 30,000.

The downtown area was under water in New Bern, a town dating to the early 18th century. Officials said more than 100 people were rescued from floods on Friday, with 60 to 75 awaiting rescue on Saturday. Some residents described a harrowing retreat as the storm hit.

"It was pitch black and I was just scared out of my mind," said Tracy Singleton, who with her family later drove through torrential rain and high winds from her home near New Bern to a hotel some 80 miles (130 km) away.

More than 20,000 people were in 157 shelters in North Carolina, with 7,000 in South Carolina shelters.

Schoolteacher Leslie Ochoa said she and her family loaded up 10 adults, 5 children, 14 goats, 10 dogs, two cats and one guinea pig and evacuated from Jacksonville, North Carolina to Columbia, South Carolina last Tuesday. As her son fed the goats in a hotel parking lot, she said she might not be able to return home until the middle of next week.

"Our friend behind our old house, they have gators swimming in the water. So yeah, not safe," Ochoa said.

The White House said President Donald Trump approved making federal funding available in some counties. Trump plans a visit to the region next week.

As the United States dealt with Florence, a strong typhoon tore across the northern tip of the Philippines on Saturday, killing at least three people, wrecking homes and triggering landslides before heading toward Hong Kong and southern China.

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