(CNN) Millions of Puerto Rico residents continue to reel from Hurricane Maria as the National Weather Service says the storm could bring "direct impacts" to the US East Coast in the coming days.

At least 10 people on the island have been confirmed killed by the storm, according to Gov. Ricardo Rosselló's office.

Much of the US commonwealth is without power and many residents are without running water. Officials have evacuated towns near the Guajataca River on the northwest part of the island, due to fears a dam could collapse

The National Hurricane Center warns the storm is marching toward the US East Coast.

"It becoming increasingly likely that some direct impacts will occur along portions of the coast next week," the National Hurricane Center said in an advisory on Saturday . "Interests in the Bahamas and along the Carolina and Mid-Atlantic coasts should monitor the progress of Maria."

Forecasters expect "dangerous surf and rip currents" along southeastern US beaches over the next several days.

"Swells from Maria are increasing along the coast of the southeastern United States and are expected to reach the mid-Atlantic coast tonight and on Sunday . ... These swells will likely cause dangerous surf and rip currents at the beach through much of next week," the hurricane center said.

A resident of the La Perla neighborhood in San Juan, Puerto Rico, surveys the damage.

The Category 3 storm is carrying maximum sustained winds of 115 mph and is 245 miles east of Eleuthera Island in the Bahamas. It is moving at 8 miles (13 kilometers) per hour.

"Maria will move away from the Bahamas into the open waters of the western Atlantic today," the center said.

The Caribbean gets socked

The storm hit Dominica, Puerto Rico, the Dominican Republic, the US Virgin Islands and the Turks and Caicos, a British overseas territory.

Residents of Roseau, capital of Dominica, walk down a street covered in debris on September 22, four days after Hurricane Maria battered the Caribbean.

It knocked out power in the US commonwealth of more than 3 million people, Puerto Rico Gov. Ricardo Rosselló said. And it could be months before the electricity returns.

"This is going to be a long road," Rosselló said Saturday.

At least 15 people are confirmed dead on Dominica, and dozens more remain missing. One person died in the US Virgin Islands, probably from drowning, authorities said. At least six people were killed in Puerto Rico, said Héctor M. Pesquera, the island's public safety director.

US President Donald Trump has pledged federal help for Puerto Rico and the US Virgin Islands.

On Saturday evening, the Puerto Rico Federal Affairs Administration confirmed that 4,000 members of the the U.S. Army Reserves have been deployed in Puerto Rico to help with Hurricane Maria recovery.

Dam weakening in Puerto Rico

On Friday afternoon, people in the northwest part of Puerto Rico were urged to evacuate because of a possible dam breach on the Guajataca River, the National Weather Service said on Twitter

Rosselló told CNN affiliate WAPA radio on Saturday that the Guajataca Dam is still holding, but he is still pleading for residents to evacuate the area.

He said the mandatory curfew remains in effect until further notice, but it will now be from 7 p.m. until 5 a.m.

At his Saturday press conference, the governor said Guajataca was without communications, meaning authorities had to physically go to residents to warn them of the potential dam breach.

"We don't know how much longer it will hold," he said. "The structure has been significantly compromised."

The governor said the island has a 20-day supply of gasoline and diesel and will install "water oasis" stations around the island. Many roads are impassable and gas stations were destroyed, he said.

Puerto Ricans living without water, communication

As Maria makes its way north, residents of Puerto Rico are beginning to assess the full extent of the storm's destruction.

Locals in the town of Maunabo, on the southeast coast of the island, could be seen lining up at a freshwater spring near the base of a mountain to fill jugs, tanks and barrels.

The spring is the only source of water in the municipality, and people wait for hours each day to get the water they need to refill toilets, take showers and wash clothes.

"Every house comes here and every day it's busy from morning to night," said Hector Labron, a resident of Maunabo. "There's no water in town."

Residents also have limited access to cell signal, causing panic among families at home and abroad who have been unable to contact their loved ones.

East of Maunabo, in Humacao, people stop their cars along the side of the road near a cell tower on a hill. It's the only access to cellphone service for miles.

"We're trying to communicate to our families in the US," Jose Flores, who traveled 17 miles to reach the tower, told CNN. "I just got connected to my daughter in Florida, and she will let the rest of the family know I'm fine."